How often to service a heat pump
Once a year is the usual answer. The Energy Saving Trust says an engineer should service a heat pump according to the manufacturer’s advice, which is usually annually, and that this is similar to a gas or oil boiler. Its installation guide repeats the point: service it yearly, keep an eye on how it behaves, particularly in colder weather, and learn what is normal so you can spot problems early.
The manufacturer’s instructions are the authority for your specific model, and they are usually tied to the warranty. If a manufacturer’s warranty requires an annual service by an approved engineer, skipping it can put the cover at risk. That is why the service terms belong on the quote, not as an afterthought; the warranty guide covers what to ask.
What a service involves
The Energy Saving Trust lists what an air source heat pump service typically covers. Individual engineers will vary, so treat this as a benchmark to compare against a service plan, not a guarantee of what any firm does.
| Check | Why it is on the list |
|---|---|
| Electrical safety check | Confirms the supply, isolators and connections are sound. |
| Thermostat operation | Checks the controls respond as they should. |
| Visual inspection of the unit | Looks for damage, corrosion or obstruction. |
| Leak and pressure checks; refrigerant top-up if needed | Refrigerant sits in a sealed circuit, so a top-up points to a leak worth finding. |
| Cleaning filters and coils | Dirt reduces airflow and heat transfer. |
| Large components: compressor, fan, pump | Checks the parts that do the work. |
| Lubricating moving parts; replacing small parts such as seals and gaskets | Done in line with the manufacturer’s guidelines. |
For a ground source heat pump the Energy Saving Trust says the service should also check the antifreeze concentration in the ground loop circuit and the flow, return temperatures and pressure in that circuit. It also advises asking your technician how to spot ground-loop issues and bleed air from the loop if needed.
What it costs
The Energy Saving Trust puts a typical heat pump service at around £150, noting that costs vary with the type of heat pump (read 8 October 2026). Treat that as a benchmark rather than a price: the cost for your house depends on the firm, the model and whether you buy a service plan. When you collect quotes, ask for the annual service price, what a call-out costs outside the service, and whether labour and parts are included. Those lines are worth comparing alongside the headline figure on the quotes checklist.
Remember that the installation price is a separate matter. The grant takes £7,500 off a qualifying air source or ground source installation but does not fund later servicing.
Servicing over the life of the system
The Energy Saving Trust says a heat pump is likely to last 20 years or more, and puts a typical service at around £150. At today’s price, a service every year for 20 years comes to about £3,000, before any inflation or repairs. That is worth including when you compare quotes, because two firms can quote similar installation prices and very different service terms.
When you collect heat pump quotes, ask each firm for the annual service price in writing, whether the manufacturer’s warranty depends on it, and what a call-out costs outside the service visit.
What you can do yourself
The Energy Saving Trust gives two simple jobs. Keep the outdoor unit clear of obstructions such as bikes, wheelie bins and leaves, because good air circulation helps efficiency and keeps running costs down. And learn the control screen: the Trust says that if something is critically wrong, the screen will tell you.
- Read the manual and the handover pack so you know the basics of the controls and the unit.
- Note the system pressure, and for a ground source system the loop pressure the installer set.
- Do not change weather-compensation or heating-curve settings unless you know what you are doing; ask the installer to review them if the house is not comfortable. The controls guide explains what they do.
- Ask whether the central heating circuit has water treatment and a filter.
Faults and warning signs
The Trust says that historically, poor installations caused most trouble in UK homes, for example systems that were not sized correctly, radiators not upgraded, narrow-bore pipework not replaced or pipework not insulated. It says these issues are much less common now, and that once a system is installed correctly you are unlikely to see much equipment failure. It adds that performance problems most often come from how the system is set up and used, for instance running a heat pump as though it were a gas boiler.
One fault message worth knowing is “heating blocked”, which the Trust says may mean the heat pump is running at temperatures that are too high, or may be a problem with the central heating system, such as faulty pumps or valves, or sludge and dirt in radiators. If you do not have water treatment and a filter, the Trust suggests fitting them. If your installer is not taking concerns seriously, it suggests contacting the manufacturer, whose technicians often have more experience of a particular model. If that fails, the complaints guide sets out the escalation route.
Questions to ask before you buy
- What does the annual service cost, and is a plan available?
- Does the manufacturer’s warranty require a service, and by whom?
- Who do I call for a fault, and what is the response commitment in writing?
- Will you explain the controls at handover and leave me the documents?
Those answers help you compare installers on more than price. The installer guide shows how to build a shortlist, and how long heat pumps last explains why upkeep matters over the full life of the unit.