Viessmann Boiler E4 Error Code — Meaning & Repair Cost (2026)
Missing or weak flame signal. Below: the most likely causes, and what the matching repair costs — Estimated national ranges with a metro localizer. Reviewed July 2026.
What E4 means
Missing or weak flame signal.
Likely causes, most common first
- Faulty flame sensor/electrode
- Low gas pressure
Base: 1 published national repair-cost guide (retrieved 2026-07) · full source registry on the methodology page · Code meaning & causes · Reviewed July 2026
What it usually costs to fix Estimated
E4 on a Viessmann boiler resolves to the boiler ignition fault / lockout problem. Viessmann parts typically run ×1.2 against the mainstream baseline (published rates from 2 local repair companies), and the ranges below already include it.
$110–$1,400 national estimate to fix the fault behind E4 (Viessmann parts ×1.2). Enter a ZIP to localize.
| Most common repair | Typical total | DIY? |
|---|---|---|
| Ignition electrode / ignitor replacement | $110–$430 | DIY possible |
| Ignition control module (lockout board) replacement | $330–$1,400 | Pro recommended |
| Gas valve replacement | $220–$1,220 | Pro recommended |
Plus a typical service-call / diagnostic fee of $75–$150, often credited toward the repair.
Pick a quality tier for a class-typical estimate, or a specific brand to override it (brand adjusts the parts portion only). Enter a ZIP or Canadian postal code to localize to your metro's labor costs. Everything updates without a page reload; no data leaves your browser except the shard lookup.
Base: 2 published national repair-cost guides (retrieved 2026-07) · full source registry on the methodology page · National base range (BLS OEWS May 2025 + BEA RPP 2024) · Reviewed July 2026 · Estimated
Codes are universal — your location changes the repair price, never the code's meaning. See the methodology for the exact localization formula and sources.
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).