HVAC Repair Cost in London (2026)
Estimated HVAC-repair cost ranges for London, in pounds, localized from the UK national base ranges using London labour-cost data (regional wage data (ONS ASHE 2025, all-employee basis; HVAC national wage base SOC 5315)). Every figure is an Estimated region-level range, never a currency-converted price from another country. Reviewed July 2026. In London, HVAC repair jobs typically run £35–£16,680 (2026), depending on the equipment and the fault.
Most common repairs & local costs
Every problem we price for the UK, grouped by appliance — the most-searched problem in each group first; expand for the rest. All ranges are in pounds, localized to London labour costs.
Gas Furnace 11 problems priced
Gas Furnace repairs in London typically run £85–£8,340 (2026).
Gas Furnace not heating / blowing cold air
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| General no-heat diagnostic and minor repair (airflow, filter, ignition or gas-valve fault) | £110–£280 | Pro recommended |
| Escalation to gas-valve or control-board fault (root cause of persistent no-heat) | £335–£780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 10 more gas furnace problems 10
Gas Furnace won't turn on / no power
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Electrical/control fault diagnosis and repair (blown fuse, failed low-voltage circuit, or wiring fault) | £110–£245 | Pro recommended |
| Control-board fault (if electrical fault isn't a simple fuse/wiring fix) | £280–£555 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace short cycling (turns on and off)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Airflow-restriction fix (filter change / blocked return) or flame-sensing fault | £110–£245 | Pro recommended |
| High-limit safety cutout replacement (persistent short-cycling) | £135–£310 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace igniter (hot surface ignitor) replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Electronic ignition electrode replacement (modern units, e.g. Johnson & Starley WarmCair) | £85–£220 | Pro recommended |
| Legacy standing-pilot ignition assembly service (1970s-80s units, e.g. Hi-VEE / Consumer Warm Air) | £110–£245 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace flame sensor cleaning / replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Flame-sensing/ionisation electrode replacement or cleaning | £85–£200 | Pro recommended |
| Flame-sensor eye replacement — legacy standing-pilot models | £110–£245 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace blower motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Fan/blower motor replacement (domestic warm-air unit) | £165–£445 | Pro recommended |
| Commercial/warehouse warm-air fan motor replacement | £335–£780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace gas valve replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Standard gas valve replacement (installed) | £200–£390 | Pro recommended |
| Gas valve replacement — wider cited UK band (proprietary/high-end valve, or simple stuck-valve free) | £220–£500 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace control board replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Control/PCB board replacement (full new board, Gas Safe engineer supplied and fitted) | £455–£780 | Pro recommended |
| Specialist board-repair service (repair rather than replace) | £90–£165 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace cracked heat exchanger replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Cracked heat exchanger repair (before replacement becomes the better option) | £1,335–£2,445 | Pro recommended |
| Whole-system replacement (the common UK outcome once repair is uneconomical) | £5,115–£8,340 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace pilot light / thermocouple won't stay lit
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Thermocouple cleaning/replacement (standing-pilot legacy units) | £110–£245 | Pro recommended |
| Gas valve replacement (root cause of last resort, standing-pilot models) | £200–£390 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Gas Furnace noisy or loud (banging, rumbling, squealing)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Fan/blower motor bearing service or replacement (rattling, humming, grinding) | £165–£445 | Pro recommended |
| Ductwork noise fix or delayed-ignition safety check (banging, ticking) | £110–£280 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning 10 problems priced
Central Air Conditioning repairs in London typically run £65–£1,670 (2026).
Central Air Conditioning not cooling / blowing warm air
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Run/start capacitor replacement | £165–£445 | DIY possible |
| Refrigerant (gas) leak repair + recharge | £165–£555 | Pro recommended |
| Condenser (outdoor) fan motor replacement | £280–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more central air conditioning problems 9
Central Air Conditioning won't turn on / no power
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Blown fuse / tripped breaker reset or fuse replacement | £65–£165 | DIY possible |
| PCB / control board replacement (fully dead system) | £335–£780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning capacitor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Run/start capacitor replacement (standard) | £165–£445 | DIY possible |
| Capacitor swap billed as a standard AC repair call-out | £175–£435 | DIY possible |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning compressor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Compressor replacement (installed) | £890–£1,670 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning refrigerant leak repair / recharge
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Minor leak repair + top-up | £165–£390 | Pro recommended |
| Extensive leak detection + repair + full recharge | £335–£890 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning frozen evaporator coil
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Airflow fix (filter clean/replace, restriction cleared) | £65–£165 | DIY possible |
| Coil cleaning / minor repair, or full evaporator coil replacement if pitted through | £780–£1,670 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning clogged condensate drain / leaking water
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Condensate drain line clear / flush | £90–£220 | DIY possible |
| Drain pipework repair / re-route (damaged or badly-fallen line) | £280–£555 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning contactor / relay replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Contactor / relay replacement | £165–£445 | DIY possible |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning condenser fan motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Outdoor fan motor replacement (standard) | £280–£665 | Pro recommended |
| Fan motor replacement, larger/harder-access outdoor unit | £445–£780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Central Air Conditioning short cycling (turns on and off)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Run/start capacitor replacement (weakening capacitor causing rapid cycling) | £165–£445 | DIY possible |
| Refrigerant recharge (low charge triggering pressure-cutoff cycling) | £165–£555 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump 10 problems priced
Heat Pump repairs in London typically run £55–£3,890 (2026).
Heat Pump not heating
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Refrigerant charge check + recharge | £220–£555 | Pro recommended |
| Reversing valve replacement | £335–£665 | Pro recommended |
| Defrost / main control board replacement | £220–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more heat pump problems 9
Heat Pump not cooling
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Capacitor or contactor replacement (reversible-mode heat pump not cooling) | £165–£445 | DIY possible |
| Refrigerant recharge (low charge affecting cooling mode) | £220–£555 | Pro recommended |
Base: GOV.UK, 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump stuck in defrost / frozen outdoor unit
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Defrost control board / sensor replacement | £220–£665 | Pro recommended |
| Reversing valve replacement (stuck mid-defrost) | £335–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump reversing valve replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Reversing valve replacement (full valve body) | £335–£665 | Pro recommended |
| Valve/sensor-level fix (minor valve issue, not a full swap) | £55–£165 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump defrost control board replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Defrost / main control board (PCB) replacement | £220–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump capacitor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Run/start capacitor replacement | £165–£445 | DIY possible |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump refrigerant leak repair / recharge
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Refrigerant recharge only (leak already minor or sealed) | £165–£555 | Pro recommended |
| Leak detection + pipe/fitting repair | £220–£780 | Pro recommended |
| Severe/compressor-area leak, full evacuation + recharge | £665–£1,335 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump compressor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Heat pump compressor replacement (standard) | £1,670–£3,335 | Pro recommended |
| Compressor replacement, major/complex case | £2,225–£3,890 | Pro recommended |
Base: 3 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump outdoor fan motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Outdoor fan motor replacement (standard) | £220–£500 | Pro recommended |
| Outdoor fan motor replacement, larger/ECM-style unit | £445–£780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Heat Pump short cycling (turns on and off)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Short-cycling diagnostic and water-side flow restoration (strainer and filter clean, TRV/bypass and volumiser check, flow rate reset) | £155–£380 | Pro recommended |
| Refrigerant leak search and recharge where low charge is tripping the pressure switch (F-Gas) | £220–£1,335 | Pro recommended |
| Pressure switch, defrost/reversing valve or control PCB replacement on the outdoor unit | £245–£1,000 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split 10 problems priced
Ductless Mini-Split repairs in London typically run £90–£1,780 (2026).
Ductless Mini-Split not cooling
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Capacitor replacement (fan runs, compressor won't start) | £165–£445 | Pro recommended |
| Refrigerant leak search + repair + recharge | £335–£890 | Pro recommended |
| Compressor replacement (outdoor unit) | £890–£1,780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more ductless mini-split problems 9
Ductless Mini-Split not heating
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Control board (PCB) or sensor fault repair (heat-mode lockout) | £200–£780 | Pro recommended |
| Refrigerant leak search + repair + recharge | £335–£890 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split refrigerant leak repair / recharge
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Leak search + flare/line-set repair + recharge | £335–£890 | Pro recommended |
| Evaporator/condenser coil replacement (non-repairable leak) | £555–£1,110 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split compressor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Compressor replacement (outdoor unit) | £890–£1,780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split indoor blower / fan motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Indoor cross-flow blower/fan motor replacement | £280–£665 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split indoor head leaking water
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Condensate drain line clear / clean | £90–£220 | DIY possible |
| Condensate pump replacement or broader drain-system repair | £165–£445 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split error code / flashing light fault
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Sensor fault / drain-fault code diagnosis + fix | £200–£390 | Pro recommended |
| Control board (PCB) replacement | £335–£1,000 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split control board / pcb replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Outdoor or indoor unit control board (PCB) replacement | £335–£1,000 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split outdoor unit not running
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Run/start capacitor replacement | £165–£445 | Pro recommended |
| Control board (PCB) replacement | £335–£1,000 | Pro recommended |
| Compressor replacement (outdoor unit) | £890–£1,780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductless Mini-Split musty or mouldy smell from the indoor unit
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Chemical deep clean of the indoor head — coil, condensate tray and casing bagged and washed, plus anti-bacterial treatment | £105–£315 | Pro recommended |
| Blower (cross-flow) wheel removal and strip clean where biofilm has hardened on the fins | £190–£500 | Pro recommended |
| Condensate drain line flush and tray disinfection | £100–£280 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler 10 problems priced
Boiler repairs in London typically run £35–£835 (2026).
Boiler no heat / not firing up
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Ignition electrode / ignitor replacement | £165–£245 | Pro recommended |
| Circulator pump replacement | £165–£445 | Pro recommended |
| Gas valve replacement | £200–£500 | Pro recommended |
| PCB / control board replacement | £335–£555 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more boiler problems 9
Boiler no hot water
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Diverter valve replacement | £200–£555 | Pro recommended |
| Circulator pump replacement (DHW side) | £220–£445 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler losing pressure
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Expansion vessel / tank replacement + repressurize | £200–£500 | Pro recommended |
| Pressure relief valve replacement | £110–£555 | Pro recommended |
| Pipe / fitting leak repair (slow pressure loss, no visible pooling) | £165–£445 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler leaking water
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Pressure relief valve replacement (dripping from discharge pipe) | £110–£555 | Pro recommended |
| Pipe / fitting / pump-seal leak repair | £165–£445 | Pro recommended |
| Heat exchanger replacement (cracked/corroded — high-ticket) | £500–£835 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler kettling (banging / rumbling noise)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Chemical / power flush (descale + sludge removal) | £335–£665 | Pro recommended |
| Pressure relief valve replacement (post-overheat check) | £110–£555 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler pilot light won't stay lit
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Thermocouple replacement | £135–£200 | Pro recommended |
| Pilot assembly cleaning / adjustment (no parts) | £35–£135 | DIY possible |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler keeps switching off (short cycling)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Expansion vessel repressurize / replace | £200–£500 | Pro recommended |
| Thermostat / control replacement or pump-speed adjustment | £110–£280 | Pro recommended |
| Power flush (sludge-driven short cycling) | £335–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler circulator pump replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Circulator / circulation pump replacement | £165–£445 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler expansion vessel / tank replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Expansion vessel / tank replacement + repressurize | £200–£500 | Pro recommended |
| Vessel recharge only (diaphragm intact, no swap needed) | £90–£200 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Boiler ignition fault / lockout
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Ignition electrode replacement | £165–£245 | Pro recommended |
| Flame sensor clean or replacement | £110–£220 | Pro recommended |
| Gas valve replacement | £200–£500 | Pro recommended |
| PCB replacement (lockout persists after electrode/sensor/valve checks) | £335–£555 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls 10 problems priced
Thermostat & Controls repairs in London typically run £45–£580 (2026).
Thermostat & Controls smart thermostat installation
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Hive or Tado thermostat installation — existing compatible wiring (no new wiring needed) | £180–£310 | DIY possible |
| Nest thermostat installation (supply + professional fit, premium tier) | £300–£425 | DIY possible |
| Smart thermostat installation with new wiring/receiver unit (older heating system, no existing compatible wiring) | £280–£500 | Pro recommended |
Base: 3 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
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Thermostat & Controls blank screen / won't power on
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Reset / flat-battery check (tripped fuse or dead batteries — cheapest, most common cause) | £45–£100 | DIY possible |
| Loose or faulty wiring connection repair | £85–£220 | Pro recommended |
| Full thermostat replacement (manual or programmable unit, internal fault) | £80–£200 | DIY possible |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls won't reach set temperature
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Diagnostic visit + minor adjustment (stuck pump, valve or fan; low-voltage wiring fault) | £55–£165 | Pro recommended |
| Thermostat relocation / recalibration (labour only — sited near a heat source, draught or direct sun) | £45–£110 | DIY possible |
| Faulty circulation pump or 2-port valve replacement (root mechanical cause) | £220–£445 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls thermostat wiring / c-wire repair
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Repair/reconnect existing thermostat wiring (loose or damaged low-voltage wire) | £65–£165 | Pro recommended |
| New wiring run / C-wire-equivalent install (no existing low-voltage wire to the thermostat location) | £100–£245 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls won't connect to wi-fi
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Router/network or hub-placement troubleshooting visit (if a professional is called in) | £65–£135 | DIY possible |
| Smart thermostat replacement (failed Wi-Fi radio/internal board, confirmed not a network issue) | £180–£410 | DIY possible |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls clicks but system won't respond
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Boiler PCB / ignition control board replacement (receiver clicks but the boiler never ignites) | £220–£445 | Pro recommended |
| Gas Safe diagnostic visit (signal reaching the boiler correctly — spark/gas-flow fault inside the boiler) | £90–£135 | Pro recommended |
| Thermostat/receiver replacement (stat's own relay contacts failed — the less common of the two causes) | £110–£335 | DIY possible |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls wrong temperature reading / miscalibrated
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Recalibrate / relocate thermostat (labour only) | £45–£110 | DIY possible |
| Thermostat replacement (drifted/failed internal sensor) | £90–£335 | DIY possible |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls zone control board / damper repair
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| 2-port zone valve actuator/motor replacement (valve head only — most common zone-control fault) | £90–£200 | Pro recommended |
| Full 2-port zone valve replacement (valve body itself seized/failed, not just the actuator) | £245–£380 | Pro recommended |
| Wiring centre / zoning junction-box replacement (multi-zone systems — the closest UK equivalent to a US zone-control board) | £110–£245 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls heating or cooling won't shut off
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Stuck motorised valve replaced — 2-port zone valve or 3-port mid-position valve (head or full body) | £200–£465 | Pro recommended |
| Room stat, cylinder stat or wiring-centre relay fault traced and replaced | £135–£425 | Pro recommended |
| Shorted or pinched thermostat cable traced and re-run | £165–£500 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Thermostat & Controls moving a thermostat to a different wall
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Relocate the room thermostat to a new wall with a fresh cable run, new back box and making-good | £165–£580 | Pro recommended |
| Convert to a wireless/RF room thermostat with a receiver at the boiler where a new cable run is impractical | £200–£510 | Pro recommended |
| Short relocation onto the existing cable at a nearby wall, plus make-good of the old opening | £100–£310 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler 10 problems priced
Air Handler repairs in London typically run £55–£4,670 (2026).
Air Handler blower not running
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Bathroom/kitchen extractor fan motor seized or failed (fan doesn't run at all) | £100–£180 | Pro recommended |
| MVHR (mechanical ventilation with heat recovery) fan motor failure — full fan replacement | £310–£780 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more air handler problems 9
Air Handler blower motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Bathroom/kitchen extractor fan motor replacement (like-for-like unit swap) | £135–£280 | DIY possible |
| MVHR fan cassette/motor replacement (ducted heat-recovery unit, higher-spec EC motor) | £310–£890 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler weak airflow
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Filter cleaning/replacement (restricted airflow from dirty filters) | £55–£165 | DIY possible |
| Ductwork/duct-run blockage or restriction clearance | £110–£280 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler leaking water (drain pan / coil)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Condensate drain clearance (blocked drain — the most common cause of an MVHR/ducted unit dripping water) | £110–£220 | Pro recommended |
| Condensate drain kit/pipework replacement or insulation (persistent leak not resolved by clearing alone) | £165–£390 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler frozen evaporator coil
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Restricted-airflow defrost fault (blocked/dirty coil or filter causing excess icing) | £110–£220 | DIY possible |
| Refrigerant leak causing low-charge icing (heat pump / ducted fan-coil refrigerant circuit) | £220–£1,335 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler noisy or loud (rattling / humming)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| MVHR/extract-fan bearing replacement (grinding, rattling — worn fan bearings) | £90–£220 | Pro recommended |
| Full fan/motor replacement (bearing wear beyond economical repair, or a standard extractor fan motor) | £165–£555 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler electric heat strip / auxiliary heat replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Electric duct heater battery replacement (in-duct resistance heater element) | £390–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler control board replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| MEV/basic ventilation control board (PCB) replacement | £100–£220 | Pro recommended |
| MVHR premium control board / regulation kit replacement | £220–£500 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler evaporator coil replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Indoor fan-coil (evaporator) unit replaced complete — pump-down, re-braze, nitrogen pressure test, vacuum and recharge | £945–£2,670 | Pro recommended |
| Concealed ducted fan-coil replacement including duct transitions, plenum rework and re-commissioning | £1,780–£4,670 | Pro recommended |
| In-warranty indoor unit/coil replacement — part supplied free, labour, refrigerant and consumables billed | £445–£1,225 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Air Handler musty smell from the vents
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| In-place chemical evaporator coil clean plus condensate tray and drain flush | £120–£335 | Pro recommended |
| Pull-and-clean: fan/blower removed, access panels off, coil and housing strip-cleaned and treated | £280–£725 | Pro recommended |
| Duct and terminal clean where the odour has carried into the duct run | £135–£665 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents 10 problems priced
Ductwork & Vents repairs in London typically run £45–£1,670 (2026).
Ductwork & Vents leaky duct sealing / repair
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Ductwork joint reseal or leak patch (single accessible section — legacy warm-air heating or MVHR ducting) | £110–£220 | Pro recommended |
| Extensive duct-run resealing (multiple leak points, larger accessible run) | £220–£500 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more ductwork & vents problems 9
Ductwork & Vents ductwork replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Legacy warm-air heating ductwork section replacement (metal trunking, ~10m run) | £335–£780 | Pro recommended |
| MVHR/ventilation ducting replacement (flexible or semi-rigid duct, ~10m run) | £165–£445 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents uneven airflow between rooms (balancing)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Full-system airflow balancing and testing (legacy warm-air heating ductwork) | £300–£645 | Pro recommended |
| MVHR duct/valve balancing visit (rebalancing supply/extract valves across rooms) | £110–£280 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents disconnected / collapsed duct repair
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Reconnect/reseal a disconnected duct run (extractor fan or MVHR ducting in a loft/void, accessible) | £65–£165 | DIY possible |
| Replace damaged/torn duct section (reconnection alone insufficient — legacy warm-air heating ductwork) | £335–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents duct damper repair
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Air brick / wall-vent damper replacement (accessible vent with integral damper flap) | £165–£280 | DIY possible |
| MVHR duct damper/balancing valve adjustment (airflow imbalance across a duct run) | £110–£335 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents vent / register replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| MVHR/ducted-system ceiling or wall vent-valve replacement (grille/diffuser swap) | £45–£135 | DIY possible |
| Multiple-vent replacement (domestic passive/ventilation grille set — e.g. soffit or roof vents) | £280–£695 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents duct insulation replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Pipe/duct lagging insulation (loft or exposed ductwork wrap, typical ~10m run) | £65–£390 | DIY possible |
| Larger MVHR loft ducting insulation retrofit (multiple exposed runs through unheated void) | £555–£1,670 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents duct cleaning
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Whole-home professional duct/ventilation cleaning (typical 2-3 bedroom home) | £110–£335 | Pro recommended |
| Larger 4+ bedroom home or heavily fouled system deep clean | £335–£665 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents adding a vent or duct run to a room
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Add one supply or extract terminal and a new duct branch to an existing MVHR / ducted ventilation system | £310–£945 | Pro recommended |
| Add one supply register and an insulated branch duct off an existing concealed ducted air-to-air heat-pump / ducted air-conditioning plenum to serve an added room (air-side ductwork only) | £390–£1,555 | Pro recommended |
| Re-commission and re-balance the system after the new outlet is added | £165–£555 | Pro recommended |
Base: 5 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Ductwork & Vents noisy ducts (banging, popping, whistling)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Fit in-line duct attenuators/silencers to the noisy branches and to the unit spigots | £200–£690 | Pro recommended |
| Airflow re-balance and static-pressure correction — restricted return opened up, dampers and terminals reset, unit speed re-commissioned | £245–£665 | Pro recommended |
| Brace, clip and seal rattling ductwork; refix loose grilles, valves and flexible-duct hangers | £165–£780 | Pro recommended |
Base: 4 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace 10 problems priced
Oil Furnace repairs in London typically run £85–£16,680 (2026).
Oil Furnace won't start / won't fire
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Nozzle, filter and fuel-line check (routine fuel-delivery no-start fix) | £100–£155 | Pro recommended |
| Ignition electrode or photocell (cad-cell) fault fix | £110–£245 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Show 9 more oil furnace problems 9
Oil Furnace not heating / no heat
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Nozzle and oil filter service (same routine fuel-delivery fix as won't-start) | £100–£155 | Pro recommended |
| Combustion-chamber/burner fault beyond routine service (persistent no-heat) | £200–£390 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace nozzle / oil filter replacement (tune-up)
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Standard annual nozzle + oil filter service | £100–£155 | Pro recommended |
| Comprehensive service (parts replaced beyond nozzle/filter, fuller clean) | £135–£200 | Pro recommended |
Base: 3 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace ignition electrode / transformer replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Ignition electrode pair replacement | £85–£220 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace oil burner motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Oil burner motor replacement | £220–£445 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace cad cell / primary control replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Photocell (cad-cell) replacement only | £100–£200 | Pro recommended |
| Full primary control (relay/control box) module replacement | £165–£390 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace puffback / soot cleanup
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Burner retune + combustion-chamber soot cleaning (root-cause HVAC-side fix) | £165–£355 | Pro recommended |
| Professional smoke/soot damage cleanup (separate restoration service, NOT an HVAC repair) | £2,225–£16,680 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace fuel oil pump replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Fuel-oil pump replacement (retail part + standard OFTEC install) | £165–£335 | Pro recommended |
| Fuel-oil pump replacement — full contractor-quoted job (documented real-world case) | £280–£465 | Pro recommended |
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace blower motor replacement
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Fan/blower motor replacement (shared hardware with gas-fired warm-air units) | £165–£445 | Pro recommended |
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
Oil Furnace cracked heat exchanger / combustion chamber
| Most common repair | Typical total (GBP) | DIY? |
|---|---|---|
| Heat exchanger replacement on an oil-fired appliance (OFTEC-registered technician) | £445–£1,670 | Pro recommended |
| Combustion chamber liner / baffle set replacement and re-commission | £245–£725 | Pro recommended |
| Condemn and replace: appliance isolated and tagged, replacement oil appliance quoted and fitted | £3,335–£6,670 | Pro recommended |
Base: 5 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · Localized via ONS ASHE 2025 (London median vs UK median, resident full-time) · Reviewed July 2026 · Estimated
How we price this for London
We take each the UK national base range and multiply it by a local index of 1.11, built from regional wage data (ONS ASHE 2025, all-employee basis; HVAC national wage base SOC 5315) (there is no the UK equivalent of the U.S. Regional Price Parity, so the price and overhead terms are held at the national baseline):
index = 1.11
The wage term uses London median vs UK median, resident full-time. Parts ship at national prices, so only the labour share moves with the region. All figures are in pounds — we never convert prices from other countries; the the UK base ranges come from UK sources. Full weights and vintages are on the methodology page.
Local rules & taxes in the UK
Sales tax on appliance repair
Repair labor is taxable here. HVAC repair labour AND parts (boilers, gas/oil furnaces, warm-air heaters, central AC, heat pumps, ductless mini-splits, ductwork, thermostats) are standard-rated for VAT at 20% (HMRC's standard rate on "most goods and services") — the same general commercial-repair rate that applies to any other trade call-out. There is no blanket reduced/zero rate for repairing an existing heating or cooling system. HVAC-SPECIFIC CARVE-OUT (the one that does not exist for plain appliance repair): the INSTALLATION of qualifying energy-saving materials — including air-source and ground-source heat pumps, and central-heating/hot-water system controls such as thermostats and thermostatic radiator valves — in residential accommodation (and charitable buildings) in Great Britain is zero-rated (0%) from 1 May 2023 until 31 March 2027, reverting to the reduced rate of 5% from 1 April 2027 onward, under VAT Notice 708/6 and the Value Added Tax (Installation of Energy-Saving Materials) Order 2022 (SI 2022/361). This 0%/5% relief applies ONLY to installing new qualifying materials, not to repairing, servicing, or maintaining an existing boiler, furnace, air conditioner, or heat pump — a normal HVAC repair call remains standard-rated at 20% regardless of what equipment it touches. Do not overclaim that HVAC repairs are 0%-rated; only genuine new-installation of the listed materials qualifies. Honesty nuance carried over from the general trader rules: the VAT-registration threshold is £90,000 taxable turnover (rolling 12 months), so many small/sole-trader heating engineers are NOT VAT-registered and add no VAT at all — quoted GBP repair prices are inconsistent on whether 20% is included; treat 20% as a ceiling on a repair quote, not a guaranteed add-on.
"20% — Standard rate — Most goods and services" (GOV.UK, VAT rates). "A zero rate applies to the installation of certain specified energy-saving materials from 1 May 2023 to 31 March 2027 ... From 1 April 2027 onwards these will revert to the reduced rate of VAT of 5%"; "Central heating and hot water system controls include: manual or electronic timers, thermostats, mechanical or electronic valves, including thermostatic radiator valves" — GOV.UK, VAT Notice 708/6: Energy-saving materials and heating equipment (https://www.gov.uk/guidance/vat-on-energy-saving-materials-and-heating-equipment-notice-7086). Registration threshold: "You must register if your total taxable turnover for the last 12 months goes over £90,000" — GOV.UK, Register for VAT.
Official source: gov.uk
Licensing & certification
No single occupational "HVAC licence" exists in the UK; instead, hazard-based certifications are legally mandatory the moment a job touches gas or refrigerant, and they cover the great majority of HVAC work. (1) GAS: work on gas heating appliances — gas boilers, gas furnaces/warm-air units, gas fires, gas water heaters, and their flues and gas connections — requires the engineer and business to be on the Gas Safe Register under the Gas Safety (Installation and Use) Regulations 1998 (SI 1998/2451), enforced by HSE — "for a gas engineering business to legally undertake gas work that is within the scope of the Regulations they must be on the Gas Safe Register"; "You need to be registered on the Gas Safe Register to work on gas fittings or gas storage vessels in the UK." Working on gas heating without registration is a criminal offence. (2) REFRIGERANT — F-GAS, the central certification for cooling/heat-pump work (this is the UK replacement for US EPA-608; never cite EPA-608 here): virtually every job that installs, services or maintains, leak-checks, recovers refrigerant from, or decommissions air-conditioning, heat-pump, or ductless mini-split (RACHP) equipment requires the individual engineer to hold a personal F-gas qualification — City & Guilds 2079 Category I–IV (or the equivalent LCL Awards Level 3 F-gas) — AND the company must separately hold F-gas company certification, renewed every 3 years, under the Fluorinated Greenhouse Gases Regulations 2015 (SI 2015/310) plus retained EU Regulation 517/2014, enforced by the Environment Agency (SEPA/NRW in Scotland/Wales). "It is against the law to work with F gas if you do not have the correct qualifications. You must have your own qualifications to work on equipment containing F gas, even if you work for someone else"; "Your company, including sole traders, must be certified by an approved body to service stationary equipment containing F gas operated by others." Unlike plain domestic-fridge repair (where a sealed small charge often keeps routine work outside F-gas scope), AC and heat-pump installation/service/decommissioning routinely opens or connects to the refrigerant circuit, so F-gas certification is the default legal requirement for this trade, not an edge case. (3) ELECTRICAL: Part P of the Building Regulations (Approved Document P) applies in England (Wales ran a shared system until its Building Regulations diverged on 31 July 2014); repairs, maintenance and like-for-like replacements are NON-notifiable, but installing a brand-new dedicated circuit or electrical supply for a heat pump or air-conditioning condenser is notifiable work ("the installation of a new circuit") requiring a registered competent person (NICEIC/NAPIT) or Building Control sign-off. Scotland (Building Standards) and Northern Ireland (Building Regulations/Technical Booklets) run separate systems with no Part P. (4) TRADER: beyond the mandatory Gas Safe and F-gas certifications above, there is no general licence to operate as an HVAC business — register with HMRC for tax, and for VAT only once taxable turnover exceeds £90,000. For heat-pump installers specifically, the Microgeneration Certification Scheme (MCS) is a voluntary quality-assurance/certification scheme (recently folded into the government's Clean Heat Market Mechanism) used to access grants such as the Boiler Upgrade Scheme and to satisfy permitted-development conditions — it is not a general legal licence to install or repair heat pumps, and no gov.uk source states it is legally mandatory; treat this MCS note as lower-confidence than the gas/F-gas/Part P facts above.
Official source: hse.gov.uk
This is general information, not legal or tax advice. Rates and rules change — confirm with the official sources above.
All HVAC repair problems
- Gas Furnace — Not heating / blowing cold air
- Gas Furnace — Won't turn on / no power
- Gas Furnace — Short cycling (turns on and off)
- Gas Furnace — Igniter (hot surface ignitor) replacement
- Gas Furnace — Flame sensor cleaning / replacement
- Gas Furnace — Blower motor replacement
- Gas Furnace — Gas valve replacement
- Gas Furnace — Control board replacement
- Gas Furnace — Cracked heat exchanger replacement
- Gas Furnace — Pilot light / thermocouple won't stay lit
- Gas Furnace — Noisy or loud (banging, rumbling, squealing)
- Central Air Conditioning — Not cooling / blowing warm air
- Central Air Conditioning — Won't turn on / no power
- Central Air Conditioning — Capacitor replacement
- Central Air Conditioning — Compressor replacement
- Central Air Conditioning — Refrigerant leak repair / recharge
- Central Air Conditioning — Frozen evaporator coil
- Central Air Conditioning — Clogged condensate drain / leaking water
- Central Air Conditioning — Contactor / relay replacement
- Central Air Conditioning — Condenser fan motor replacement
- Central Air Conditioning — Short cycling (turns on and off)
- Heat Pump — Not heating
- Heat Pump — Not cooling
- Heat Pump — Stuck in defrost / frozen outdoor unit
- Heat Pump — Reversing valve replacement
- Heat Pump — Defrost control board replacement
- Heat Pump — Capacitor replacement
- Heat Pump — Refrigerant leak repair / recharge
- Heat Pump — Compressor replacement
- Heat Pump — Outdoor fan motor replacement
- Heat Pump — Short cycling (turns on and off)
- Ductless Mini-Split — Not cooling
- Ductless Mini-Split — Not heating
- Ductless Mini-Split — Refrigerant leak repair / recharge
- Ductless Mini-Split — Compressor replacement
- Ductless Mini-Split — Indoor blower / fan motor replacement
- Ductless Mini-Split — Indoor head leaking water
- Ductless Mini-Split — Error code / flashing light fault
- Ductless Mini-Split — Control board / PCB replacement
- Ductless Mini-Split — Outdoor unit not running
- Ductless Mini-Split — Musty or mouldy smell from the indoor unit
- Boiler — No heat / not firing up
- Boiler — No hot water
- Boiler — Losing pressure
- Boiler — Leaking water
- Boiler — Kettling (banging / rumbling noise)
- Boiler — Pilot light won't stay lit
- Boiler — Keeps switching off (short cycling)
- Boiler — Circulator pump replacement
- Boiler — Expansion vessel / tank replacement
- Boiler — Ignition fault / lockout
- Thermostat & Controls — Smart thermostat installation
- Thermostat & Controls — Blank screen / won't power on
- Thermostat & Controls — Won't reach set temperature
- Thermostat & Controls — Thermostat wiring / C-wire repair
- Thermostat & Controls — Won't connect to Wi-Fi
- Thermostat & Controls — Clicks but system won't respond
- Thermostat & Controls — Wrong temperature reading / miscalibrated
- Thermostat & Controls — Zone control board / damper repair
- Thermostat & Controls — Heating or cooling won't shut off
- Thermostat & Controls — Moving a thermostat to a different wall
- Air Handler — Blower not running
- Air Handler — Blower motor replacement
- Air Handler — Weak airflow
- Air Handler — Leaking water (drain pan / coil)
- Air Handler — Frozen evaporator coil
- Air Handler — Noisy or loud (rattling / humming)
- Air Handler — Electric heat strip / auxiliary heat replacement
- Air Handler — Control board replacement
- Air Handler — Evaporator coil replacement
- Air Handler — Musty smell from the vents
- Ductwork & Vents — Leaky duct sealing / repair
- Ductwork & Vents — Ductwork replacement
- Ductwork & Vents — Uneven airflow between rooms (balancing)
- Ductwork & Vents — Disconnected / collapsed duct repair
- Ductwork & Vents — Duct damper repair
- Ductwork & Vents — Vent / register replacement
- Ductwork & Vents — Duct insulation replacement
- Ductwork & Vents — Duct cleaning
- Ductwork & Vents — Adding a vent or duct run to a room
- Ductwork & Vents — Noisy ducts (banging, popping, whistling)
- Oil Furnace — Won't start / won't fire
- Oil Furnace — Not heating / no heat
- Oil Furnace — Nozzle / oil filter replacement (tune-up)
- Oil Furnace — Ignition electrode / transformer replacement
- Oil Furnace — Oil burner motor replacement
- Oil Furnace — Cad cell / primary control replacement
- Oil Furnace — Puffback / soot cleanup
- Oil Furnace — Fuel oil pump replacement
- Oil Furnace — Blower motor replacement
- Oil Furnace — Cracked heat exchanger / combustion chamber
Return to the the UK HVAC repair guide.
Reviewed by a Red Seal–certified appliance technician who also holds a Technical Safety BC gas ticket (Gas-C) and an ODS/halocarbon refrigerant ticket (CFC/HCFC/HFC).