If you own an air source heat pump, we recommend having it professionally serviced at least once a year.

But there’s an important difference between simply servicing a heat pump and checking that the whole heating system is actually working as efficiently as it should.

A heat pump can be perfectly operational and still cost considerably more to run than necessary because of high flow temperatures, incorrect controls, poor system balancing or problems elsewhere in the heating system. If those symptoms are already affecting comfort or running costs, an independent heat pump diagnostic review can identify the cause before you spend money on changes.

That’s why a good annual service shouldn’t just be about checking the outdoor unit.

When is the best time to service a heat pump?

We generally recommend servicing your heat pump before the main heating season, ideally around September or October.

During summer, your heat pump may have spent months doing very little heating. Zone valves, TRVs, circulation components and other parts of the heating system may not have been operating in the same way they will during winter.

The last thing you want is to discover a problem on the first genuinely cold night of the year.

A pre-winter service gives you the opportunity to:

• Check the heat pump is operating correctly

• Run the system properly in heating mode

• Check system pressures and expansion vessels

• Check filters and strainers

• Test zone valves

• Check TRVs and radiators

• Review heating controls

• Check weather compensation settings

• Review flow temperatures

• Balance the heating system where required

• Identify potential problems before winter

Is a standard heat pump service enough?

Not always.

One of the biggest mistakes we see is treating a heat pump like a boiler.

With a boiler, an annual service is primarily concerned with checking the appliance itself is safe and operating correctly.

With a heat pump, the heating system around it has a huge influence on efficiency.

The heat pump could be working exactly as the manufacturer intended, but if it’s being asked to produce unnecessarily high flow temperatures or the heating system isn’t balanced correctly, your running costs can still be higher than they need to be.

That’s why we believe a heat pump service should look at the whole system.

Your flow temperature matters

One of the most important things we look at is flow temperature.

Generally, the lower the temperature your heat pump needs to produce while still keeping your home comfortable, the more efficiently it can operate.

As a rough rule of thumb, reducing heat pump flow temperature by 1°C can improve efficiency by around 2–3%, although the actual improvement will vary depending on the heat pump, property, weather conditions and heating system.

This means there can be a substantial difference between a system unnecessarily running at 50°C and one that’s been properly designed, balanced and configured to keep the property comfortable at a lower temperature.

Simply checking that the heat pump “works” doesn’t tell you whether it’s working efficiently.

Your heat loss should be part of the conversation

To optimise a heating system properly, it helps to understand how much heat the property actually requires. An up-to-date room-by-room heat loss survey gives that evidence and can show whether each room has enough emitter capacity at an efficient flow temperature.

A room-by-room heat loss calculation allows us to compare the heat requirement of each room against its radiators or other heat emitters.

This can help identify why:

• Certain rooms never get warm enough

• The whole system needs a high flow temperature

• One room overheats while another remains cold

• The heat pump appears to run inefficiently

• Electricity consumption seems higher than expected

Sometimes improving the performance of a heat pump isn’t about changing the heat pump at all.

A radiator change, control adjustment, system balancing or relatively small plumbing alteration can sometimes allow the entire system to operate more effectively.

If you are reviewing a proposed installation or comparing an installer’s specification, our pre-installation design review can check the heat-loss assumptions, heat pump size and design choices before work begins.

More than an annual service

This is exactly why we created Heat Pump Service Plus.

Rather than visiting once a year, servicing the heat pump and disappearing until next year, we look at the bigger picture.

Service Plus includes:

• Annual heat pump and heating system service

• Room-by-room heat loss assessment if you don’t already have a suitable one

• System efficiency review

• Flow temperature optimisation

• Heating control review

• System balancing where required

• Pre-winter heating test

• Checks of zone valves, TRVs and expansion vessels

• Clear recommendations for any improvements

• Simple guidance showing you how to operate your heat pump efficiently

• Direct access to experienced heat pump technical support throughout the year

If we recommend physical improvements, there is no obligation to use us to carry them out.

You can use your own plumber or electrician, and we’re happy to provide the technical information needed to help them make the recommended changes.

What happens if something goes wrong after the service?

That’s another reason we’ve structured Service Plus differently.

Once you’re a member, you have a direct technical support number for our heat pump team throughout the year.

If something doesn’t seem right, you don’t necessarily need to wait for another service visit or start searching for somebody who understands your particular system.

We’ll first try to understand and diagnose the problem remotely.

Where a physical visit is required, we can help establish what is likely to be needed and, if you’re using a local engineer, help provide them with useful information about your system.

For an installed system that is repeatedly faulting, short-cycling or failing to heat the home properly, see our Fix My Heat Pump diagnostic service for an independent technical assessment.

How much does Heat Pump Service Plus cost?

Your first year costs £360 + VAT, paid upfront.

One month later, payments of £30 + VAT per month begin. These payments build towards your following year’s membership, meaning your next annual service and continued technical support are funded in advance.

The aim isn’t simply to service your heat pump once a year.

It’s to help you keep the whole system working properly, efficiently and reliably throughout its life.

When was your heat pump last properly checked?

If your heat pump hasn’t been serviced recently, or it’s technically working but you’re not convinced it’s running as efficiently as it should, we can take a look at the complete system.

Start with a quick video call with one of our heat pump experts. We’ll discuss your system, any concerns you have and explain how Service Plus works.

Enquire About Heat Pump Service Plus