Do Air Source Heat Pumps Need Servicing? What Every Owner Needs to Know

Short answer: yes. An air source heat pump needs a professional service once a year to keep it running efficiently, protect your manufacturer's warranty and avoid expensive breakdowns. Skipping it is one of the most common and most costly mistakes heat pump owners make.

If you've recently had an air source heat pump (ASHP) fitted, or you're weighing one up, you've probably heard that heat pumps are "low maintenance." That's true compared with a gas boiler - but "low maintenance" doesn't mean "no maintenance." Below, we explain exactly why your heat pump needs servicing, how often, what a proper service involves, and what happens if you leave it.

Do air source heat pumps need servicing? The short answer

Yes. Every major heat pump manufacturer recommends an annual service carried out by a competent engineer, and most require it to keep your warranty valid. A yearly service keeps efficiency high, catches small faults before they become breakdowns, and gives you documented proof of upkeep if you ever need to make a claim.

Think of it the same way you'd think of an MOT and service for your car. The heat pump might run all year without complaint, but that doesn't mean everything under the casing is still performing as it should.

"But I thought heat pumps were low-maintenance?"

They are - relatively. A heat pump has fewer moving parts than a combustion boiler and nothing burning inside it, so there's less to go wrong day to day. But an ASHP is still a working refrigeration system with several things that drift, wear or clog over time:

• Refrigerant circuit — the sealed system that moves the heat. Performance can quietly drop if pressures aren't where they should be.

• Glycol / antifreeze — the inhibited fluid protecting your system from freezing and corrosion loses strength over time and needs checking and topping up.

• Filters and the magnetic filter — trap debris and sludge that would otherwise reduce flow and efficiency.

• Condensate drainage — can block with dirt or freeze, causing water to back up.

• Fans, coils and the outdoor unit — collect leaves, dust and debris that reduce airflow and make the pump work harder.

• Controls, sensors and firmware — settings and weather compensation curves that quietly determine how much you pay to run it.

None of these announce themselves. They simply make your heat pump slowly less efficient and more expensive to run, until something fails.

How often should an air source heat pump be serviced?

Once a year is the standard. Most manufacturers specify an annual service, and some are more prescriptive - so it's always worth checking your handover pack or warranty terms.

The best time to book is late summer or early autumn, before the heating season starts. That way any issue is picked up while it's cheap and easy to fix, rather than in the middle of a cold snap when your heating is working hardest and engineers are busiest.

What does an air source heat pump service include?

A thorough ASHP service is much more than a quick visual glance. A proper annual service should cover:

• Checking system and refrigerant operating pressures and performance

• A leak check on the refrigerant circuit where required

• Testing glycol / antifreeze concentration and inhibitor levels, and topping up if needed

• Cleaning or replacing filters, including the magnetic filter

• Clearing and checking the condensate drain

• Cleaning the outdoor unit, coils and fan, and clearing debris

• Inspecting electrical connections, wiring and safety devices

• Checking the expansion vessel and system pressure

• Reviewing flow temperatures, weather compensation and controls so the system runs as efficiently as possible

• Checking sensors, firmware and error logs for anything flagged

• A full safety check and a written service record for your warranty file

That last point matters: a documented service is what keeps your warranty enforceable.

Servicing and your warranty — the bit that catches people out

Here's the detail many owners miss. Most heat pump warranties are conditional on the unit being serviced every year by a suitably qualified engineer, with records kept. Miss a service — or lose the paperwork — and the manufacturer can refuse a future claim, even if the fault has nothing to do with the missed service.

On a system that can cost several thousand pounds, that's a serious risk to carry just to save the price of one annual visit.

What happens if you don't service your heat pump?

Leaving your ASHP unserviced tends to cost you in four ways:

• Higher bills. A heat pump that's lost efficiency uses more electricity for the same heat. The extra running cost can quietly outweigh the price of a service.

• Avoidable breakdowns. Small issues — low glycol, a blocked condensate, a clogged filter — turn into failures, usually at the worst time of year.

• A voided warranty. As above, a missed service can invalidate cover.

• A shorter lifespan. A well-maintained heat pump should give you many years of reliable service. A neglected one won't.

Can I service my air source heat pump myself?

You can — and should — do basic housekeeping between services: keep the outdoor unit clear of leaves and debris, make sure nothing is blocking the airflow, and keep an eye on your system pressure gauge.

But a full annual service needs a qualified engineer. Crucially, any work involving the sealed refrigerant circuit legally requires an F-Gas certified engineer — it isn't a DIY job, and getting it wrong is both dangerous and against the regulations. A professional also has the tools to measure performance properly and spot problems you simply can't see.

How much does an air source heat pump service cost?

A one-off ASHP service typically runs to a few hundred pounds, depending on your system and where you are. The catch with pay-as-you-go is that it's easy to forget, easy to put off — and you're on your own if something goes wrong between services.

That's exactly why most owners prefer a maintenance plan: it spreads the cost into a small monthly payment, makes sure the annual service actually happens, and gives you a specialist to call when you need one.

The easy way to stay on top of it — Renewable Helpline plans

Renewable Helpline is a specialist air source heat pump maintenance service. Our plans are service and maintenance agreements — not insurance — designed to keep your heat pump running at its best, year after year, without you having to think about it:

• Essential Care — from £15/month: your annual ASHP service, handled by specialists, plus support when you need it.

• Complete Care — £18/month (most popular): everything in Essential Care, with your hot water cylinder covered too.

• Priority Care — £30/month: our most comprehensive plan, with labour included.

Every plan means your annual service is booked and done, your warranty stays protected, and there's an ASHP expert on the end of the phone when you need one. Plans are available for mainland UK private domestic properties, with a 12-month minimum term.

Want your heat pump looked after properly? Call us on 0800 135 7663, or email hello@renewablehelpline.co.uk — and we'll get your annual service sorted.

Frequently asked questions