UK Heat Pump Finder
What heat pump repairs cost in the UK
Most repairs land between £150 and £600, with the average around £500. The spread is wide because it depends entirely on which component has failed.
| Item | Typical UK cost |
|---|---|
| Callout / diagnostic visit | From around £100 |
| Engineer hourly rate | ~£40/hour average |
| Simple fault (e.g. electrical connection) | From ~£150 |
| Typical repair | ~£500 average |
| Compressor replacement | ~£2,000 |
| Annual service | £100-£200 |
| Service/maintenance plan | Up to ~£25/month |
Typical UK figures as of 2026. Parts are often charged separately from labour — always confirm before work starts.
The most common faults
- Low refrigerant levels — often a sign of a leak. A recharge without finding and fixing the leak is only a temporary fix, so it's worth asking specifically whether the leak source was located.
- Faulty thermostat or controls — among the cheaper faults to put right.
- Ice build-up on the outdoor unit — distinct from a normal defrost cycle. Persistent ice that doesn't clear is worth investigating.
- Electrical connection faults — usually at the lower end of the cost range.
- Blocked or frozen condensate drain — common in winter, and often preventable.
Many of these get picked up during a routine annual service before they turn into a breakdown, which is the main practical argument for servicing.
Check these before booking a callout
Worth ruling out first — a callout charge for something on this list is an avoidable £100.
- Is the outdoor unit obstructed? Leaves, debris or overgrown vegetation restrict airflow. Keep roughly a metre of clearance.
- Is the condensate drain blocked or frozen? A frequent winter cause of problems.
- Have any settings been changed? Flow temperature and weather compensation are set deliberately by your installer. Adjusting them is a common cause of self-inflicted performance problems — if someone's changed them, that may be the whole issue.
- Have bills risen without the weather getting colder? That's a genuine signal worth investigating rather than ignoring.
- Is it actually a fault? See the normal-behaviour list below.
Normal behaviour that isn't a fault
| What you're seeing | Why it happens |
|---|---|
| Radiators feel warm, not hot | Heat pumps run at 35-45°C vs a boiler's 60-70°C. This is what makes them efficient. |
| Steam from the outdoor unit | The defrost cycle melting ice off the heat exchanger. Typically lasts 5-10 minutes. |
| Runs continuously rather than cycling | Designed behaviour — steady low output is more efficient than short hot bursts. |
| Audible fan and compressor noise | Modern units run around 40-60 dB. Louder on the coldest days when working hardest. |
| Higher bills in a cold snap | Efficiency drops as outdoor temperatures fall. Expected, not a fault. |
More detail on all of these in our heat pump myths guide.
Repair or replace?
A well-maintained heat pump typically lasts 20-25 years. Rough guidance:
- Repair — unit under 10 years old, faults infrequent, component cost reasonable against the system's remaining life.
- Consider replacing — well into its second decade, breakdowns becoming regular, or a major component such as the compressor has gone.
Finding someone qualified
Repairs don't legally require an MCS-certified installer the way a grant-funded installation does — but the installers listed on this site are cross-checked against the MCS register, which is a reasonable proxy for competence on heat pump systems specifically rather than general plumbing.
Worth asking before booking:
- Do you work on my specific make and model?
- What's the callout charge, and does it come off the repair cost if I go ahead?
- Will you confirm the diagnosis and cost before starting work?
- For refrigerant work — are you F-Gas certified? (Legally required for refrigerant handling.)
Find heat pump specialists in your area — every listing cross-checked against the official MCS register.
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