How Long Should a Heat Pump Last?
With annual servicing, a quality air source heat pump should last 15–20 years. Some well-maintained systems continue to operate efficiently beyond 20 years. Compressors — the most critical component — typically have a lifespan of 15–20 years. The overall system lifespan depends heavily on maintenance quality, installation standards, and operating conditions.
Signs Your Heat Pump May Need Replacing
- Age over 15 years: As systems age, efficiency declines and parts become harder to source
- Frequent breakdowns: More than one significant repair per year suggests a system nearing end of life
- Declining efficiency: Rising electricity bills without changes in usage or energy prices
- Compressor failure: Compressor replacement on an older system may cost more than a new unit after the BUS grant
- Refrigerant phase-out: Older systems using R22 or R407C refrigerant face increasing parts costs as these refrigerants are phased out
- Parts no longer available: Manufacturer discontinued the model and parts are unavailable
Repair vs Replacement: The 50% Rule
A useful rule of thumb: if the repair cost exceeds 50% of the replacement cost, replacement is usually the better financial decision — especially for systems over 10 years old. Factor in the £7,500 BUS grant, which significantly reduces the net cost of a new system.
Getting a New System
If you’re replacing an existing heat pump with a new one, you may still be eligible for the BUS grant provided the original fossil fuel heating system has been replaced (i.e., you’re not switching from one heat pump to another as your primary system). Check with an MCS installer for current eligibility.
