Heat Pump: Repair or Replace? (2026 cost comparison)
The rule of thumb, from Consumer Reports: don't spend more than 50% of a comparable new unit on fixing the old one. For a heat pump, that 50% line is about $3,500–$15,000 NZD — a new unit runs $7,000–$30,000 NZD and typically lasts 10–15 years. If a repair quote lands under that line and the heat pump is not yet past its expected life, repair usually wins. Reviewed July 2026.
Repair vs. replace, side by side Estimated
| Cost | Estimated range |
|---|---|
| Typical repair (this heat pump, all faults we price) | $130–$3,500 NZD |
| New heat pump (unit only) | $7,000–$30,000 NZD |
| The 50% line half a comparable new unit | $3,500–$15,000 NZD |
Repair: min–max of every heat pump fault we price (sources on each linked problem page) · New unit: Auckland Heat Pump Services, Airmax, Weka Electrical · Lifespan 10–15 years: Consumer NZ, Weka Electrical, Auckland Heat Pump Services · 50% rule: Weka Electrical · Reviewed July 2026 · Estimated
Age × repair-cost worksheet Estimated
Find your heat pump's age down the side and your repair quote across the top. The cell is the way the 50% rule points — Estimated guidance, not advice.
| Age of unit | Repair < 30% of a new heat pumpunder $2,100–$9,000 NZD | Repair 30–50%$2,100–$9,000 NZD – $3,500–$15,000 NZD | Repair > 50%over $3,500–$15,000 NZD |
|---|---|---|---|
| Under 6 years first half of typical life | Repair likely | Repair likely | Compare quotes |
| 6–15 years second half, under typical lifespan | Repair likely | Compare quotes | Replace likely |
| Over 15 years at or beyond typical lifespan | Compare quotes | Replace likely | Replace likely |
How this is built: we apply the 50% rule (Weka Electrical) — spend no more than half a comparable new unit's cost on a repair — with its lifespan corollary (replacement is favored once the unit is past the midpoint of its expected life and the quote tops 50%). Columns are your repair quote as a share of a new heat pump ($7,000–$30,000 NZD); the $3,500–$15,000 NZD and $2,100–$9,000 NZD thresholds are just 50% and 30% of that range. Rows use the midpoint of the expected life (about 6 years — halfway through a typical 13-year lifespan) and the top of the sourced 10–15 years range (15 years). Nothing here is a per-unit price or a recommendation — it is a transparent reading of the rule.
This taxonomy id maps to the DUCTED / whole-home reversible heat pump, which is why its new_unit_nzd range ($7,000–$30,000, supplied and installed) is far higher than the single high-wall split priced under 'ductless-mini-split' — the two share the same service life in New Zealand but not the same installed cost. The range brackets what the three cited cost guides actually document: Weka Electrical's ducted '$7,000 – $20,000' sets the low end, Auckland Heat Pump Services' 'can exceed $25,000 for larger properties' sits inside it, and Airmax's 'typical 4-6 zone family home' band '$15,000-$30,000+ installed' sets the $30,000 top (Airmax's premium and very-large-home figure runs higher still and is left outside the carried ceiling). On GST: only Weka Electrical's cost table explicitly labels its figures 'incl. GST'; the Auckland Heat Pump Services and Airmax prices are consumer supplied-and-installed quotes assumed GST-inclusive per standard NZ retail price-display practice, not separately confirmed on those two pages. The headline 10-15-year service-life range is Consumer NZ's, chosen because it is the independent consumer body's published figure and because it is the number the Consumer Guarantees Act durability test and the spare-parts-holding duty get argued against in New Zealand. The installer sources sit at or above it and are disclosed rather than averaged in: Weka Electrical says 12-15 years typical and up to 20 with servicing; Auckland Heat Pump Services says 15-20 years for modern units (25 for some new models) and 10-15 for older ones. Read the spread as vintage-dependent — pre-2010 units at the bottom, current inverter units at the top — not as a disagreement about the same equipment. New Zealand servicing convention behind these figures: an annual professional service (Varcoe: 'a professional service once every 12 months', six-monthly for high-use, coastal or pet households), with Varcoe also noting that 'Most manufacturer warranties for heat pumps in New Zealand include a clause requiring regular professional maintenance' and naming Mitsubishi Electric, Daikin and Panasonic as recommending it as a warranty condition (https://www.varcoe.co.nz/blogs/heat-pump-servicing-auckland-costs-guide/, retrieved 2026-07-19).
One more thing before you replace
A newer heat pump can cut energy and water use, which shifts the math on an older unit even when a repair is cheap: ENERGY STAR notes clothes washers over ~10 years and refrigerators over ~15 years are common efficiency-driven replacements.
Energy note: · Reviewed July 2026 · Estimated · Informational only
Price the repair first
Before you decide, get the likely repair figure for the exact fault — each page localizes to your metro:
- Full heat pump cost guide
- Not heating
- Not cooling
- Stuck in defrost / frozen outdoor unit
- Reversing valve replacement
- Defrost control board replacement
- Capacitor replacement
- Refrigerant leak repair / recharge
- Compressor replacement
- Outdoor fan motor replacement
- Short cycling (turns on and off)
Estimated ranges — see the methodology for how we build the repair figures and their named sources. This page is informational and is not repair, purchasing, or financial advice.
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).