What Should Be Included in an Air Source Heat Pump Service?

A proper air source heat pump service should involve much more than checking the outdoor unit, cleaning it and confirming that it still works.

Your heat pump is only one part of a complete heating system. Radiators, pipework, controls, zone valves, filters, expansion vessels, system pressure and even the settings inside the controller can all affect how efficiently and reliably your heat pump operates. That’s why we believe a good heat pump service should look at the whole system, not just the heat pump.

What Should an Annual Heat Pump Service Include?

The exact requirements vary between manufacturers and systems, but a thorough service should typically include checks such as:

• Visual inspection of the heat pump

• Outdoor coil condition

• Condensate drainage

• System pressure

• Expansion vessel condition and pressure

• Filters and strainers

• Circulation and flow

• Zone valve operation

• TRVs and radiators

• Heating controls and thermostats

• Weather compensation settings

• Flow and return temperatures

• Hot water settings

• Heating mode operation

• System balancing where required

• Any visible leaks or signs of deterioration

• Review of fault history where available

But for us, that’s only part of the job.

Is Your Heat Pump Actually Running Efficiently?

There’s an important difference between a heat pump that works and a heat pump that’s working as efficiently as it reasonably can. You could have a system with no fault codes and a perfectly healthy outdoor unit, but still be spending more on electricity than necessary. Common causes include flow temperatures set unnecessarily high, poorly balanced radiators, incorrect weather compensation settings, undersized radiators, incorrect control settings, unnecessary zoning, poor system flow, dirty filters, incorrect hot water settings and controls fighting against each other.

A basic heat pump service may not catch any of this because technically nothing is broken. But it can make a real difference to how your system performs day to day, and it’s why we’ve written separately about why heat pumps sometimes cost more to run than expected, since a lot of the same causes show up there too.

Flow Temperature Is One of the First Things We’d Look At

Heat pumps generally operate more efficiently at lower flow temperatures. As a rough rule of thumb, reducing flow temperature by 1°C can improve efficiency by around 2 to 3%, although the actual improvement varies depending on the property, heat pump, heating system and weather conditions. So if your system is running at a higher temperature than it actually needs, there may be an opportunity to reduce running costs without replacing the heat pump at all.

The trick isn’t simply turning the temperature down. We need to establish how low your particular system can operate while still keeping every room comfortable, which is exactly the reasoning behind our guide on what flow temperature your heat pump should run at. That’s where understanding the property becomes important.

We Look at the Heat Loss Too

A room-by-room heat loss calculation tells us approximately how much heat each room needs during colder weather. We can then compare that against the radiators or other heat emitters installed in each room. This helps us understand whether your system could potentially operate at a lower flow temperature.

For example, if one radiator is significantly undersized, the entire heating system might be running hotter simply to keep that one room comfortable. Replacing or improving that radiator could potentially allow the whole system to operate at a lower temperature. That’s why our heat pump service plan includes a room-by-room heat loss assessment where a suitable one isn’t already available.

We’ll Actually Run the Heating

This sounds obvious, but it’s particularly important before winter. A heat pump can spend much of the warmer part of the year predominantly producing hot water. Then the temperature drops and suddenly the entire heating system is expected to operate again. That’s when problems with things like zone valves, TRVs, circulation and controls can become apparent, and it’s also often when a blocked or dirty filter that’s been quietly restricting flow finally shows itself.

We prefer to service and test systems before the main heating season, normally around September or October. We’ll run the system in heating mode and check that heat is actually getting where it’s supposed to go. Finding a problem in September is considerably better than discovering it on a freezing evening in January.

What Happens If We Find Something That Could Be Improved?

We’ll tell you. That doesn’t automatically mean you need a new heat pump or thousands of pounds of work. Sometimes the recommendation could be relatively simple: change a radiator, adjust a control setting, rebalance the system, alter a flow temperature, correct a zone valve issue, clean or replace a filter, or make a small plumbing alteration.

We’ll explain what we’ve found, why we think it matters and what we’d recommend doing. And importantly, you don’t have to use us to carry out the work. Where we’re able to offer the physical work, we can provide a price. Alternatively, you’re completely free to use your own plumber or electrician. We’re also happy to provide them with the relevant technical information so everyone is working towards the same goal, getting your heat pump system running as well as possible. If your heat pump already has a genuine fault rather than a general efficiency question, that’s a different situation, and our Fix My Heat Pump service is built for that instead.

What Is Heat Pump Service Plus?

We created Heat Pump Service Plus because we wanted to offer something beyond a conventional once-a-year heat pump service. It combines annual heat pump servicing, wider heating system checks, a room-by-room heat loss assessment where required, flow temperature optimisation, control and weather compensation review, heating system balancing where required, a pre-winter heating test, efficiency recommendations, simple step-by-step operating guidance, and direct technical support throughout the year.

Once you’re a Service Plus customer, you also have access to a direct technical support number. During normal working hours, Monday to Friday, 8am to 6pm excluding bank holidays, we aim to respond to urgent technical support requests within one working hour. If something goes wrong, we’ll first see whether we can diagnose or resolve it remotely. If you need somebody physically at the property, we’ll help you understand what is likely to be required and can work with your local engineer where appropriate.

How Much Does Heat Pump Service Plus Cost?

The first year is £360 + VAT, paid upfront. One month later, your £30 + VAT monthly payments begin. Those payments fund the following year’s membership, keeping your next annual service and ongoing technical support covered in advance. So rather than paying somebody once a year simply to check the heat pump, you have ongoing support from people who understand heat pumps and the heating systems they’re connected to. If you’re comparing this heat pump service cost against a standalone annual visit elsewhere, it’s worth weighing what’s actually included on each side before deciding.

If you’re still planning an installation rather than looking after one that’s already in, a service plan isn’t the right starting point yet, our Pre-Installation Design Review is designed for that stage instead.

Don’t Just Service the Heat Pump. Look After the System.

A heat pump can only perform as well as the heating system around it allows. That’s why our approach isn’t simply “is the heat pump working?” We also want to know whether the whole system is working properly, and whether we could make it work better.

If you’d like us to take a proper look at your heat pump and heating system, start with a quick video call with one of our experts.

Enquire About Heat Pump Service Plus →

Frequently Asked Questions About Heat Pump Servicing