Air Source Heat Pump Servicing: How Often & What's Involved?

You've made the switch to an air source heat pump. Now the question is: how do you keep it running at its best?

Like any home heating system, your air source heat pump needs regular servicing to stay efficient, reliable, and under warranty. The good news is that heat pump servicing is straightforward, affordable, and far less stressful than most homeowners expect. This guide covers everything you need to know — how often, what's involved, what it costs, and what you can do yourself between visits.

Do Air Source Heat Pumps Need Servicing?

Yes — and it's more important than most people realise.

A well-maintained air source heat pump can last 15 to 20 years. Neglect the servicing, and you could see that figure drop significantly — along with your system's efficiency and your warranty protection.

Here's why annual servicing matters:

• Efficiency: According to Viessmann, a poorly maintained heat pump can use up to 25% more electricity than one that's properly serviced. That's a meaningful hit to your energy bills over a full heating season.
• Warranty: Most manufacturer warranties (typically 7–10 years) require documented annual servicing. Miss a single visit, and you could void your warranty entirely.
• Lifespan: Regular maintenance catches small issues before they become expensive repairs. A minor refrigerant imbalance or a blocked filter left unchecked can cause serious system damage over time.

Think of it like servicing a car. You could skip it for a year or two. But eventually, you'll pay far more to fix what an annual service would have caught early.

How Often Should You Service an Air Source Heat Pump?

Once a year — that's the standard recommendation across the industry, and it's what most manufacturer warranties require.

The ideal time is late summer or early autumn, just before your system starts working hard through the colder months. That way, any issues are identified and fixed before the heating season, not halfway through it.

A few situations where you might consider more frequent checks:

• Your system is over 10 years old and handling both heating and hot water year-round
• Your heat pump is in a location with heavy leaf fall or airborne debris that clogs the outdoor unit
• Your manufacturer's warranty terms specifically require biannual inspections (check your documentation)

For most UK households, one service per year is exactly right.

What's Included in an Air Source Heat Pump Service?

A professional air source heat pump service typically takes 60 to 90 minutes and covers both the indoor and outdoor components of your system.

Here's exactly what a thorough engineer should check and do:

Full Service Checklist — What Your Engineer Should Cover

Important: Any work involving the refrigerant circuit must be carried out by an F-Gas certified engineer. This isn't optional — it's a legal requirement in the UK.

If a company offers a "heat pump service" at a suspiciously low price that doesn't include a refrigerant check, ask questions. A proper service cannot skip this step.

How Much Does Air Source Heat Pump Servicing Cost?

A standard annual air source heat pump service in the UK typically costs £150 to £300, with most homeowners paying around £200 for a mid-range system.

Costs vary depending on your location, the size and type of your heat pump, and the company carrying out the work.

One-Off Service vs Service Plan: Which Is Better Value?

For most new heat pump owners, a monthly service plan offers the best value. You get the annual service included, priority response if something goes wrong, and a predictable monthly cost that's easier to budget for than a lump sum.

For systems under 5 years old with no history of issues, a one-off annual booking is perfectly reasonable.

Who Should Service Your Air Source Heat Pump?

Not just any heating engineer — you need someone with specific qualifications.

What to look for:

• MCS accreditation — the Microgeneration Certification Scheme certifies installers and engineers who work on renewable heating systems. This is particularly important if you received a grant through the Boiler Upgrade Scheme, as MCS-certified work may be required to keep your grant documentation valid.
• Manufacturer training — some brands (Mitsubishi, Vaillant, Daikin) offer manufacturer-specific training. An engineer familiar with your brand will service it more effectively.
• F-Gas certification — only required if your system develops a refrigerant leak. Gas leaks are very uncommon in hermetically sealed monoblock heat pumps, but if one does occur, the repair must be carried out by an F-Gas certified engineer.

Our MCS-accredited installers at Switch Together carry out heat pump servicing as well as new installations. If you're not sure where to find a qualified engineer in your area, that's a good place to start.

What Can I Do Myself? DIY Heat Pump Maintenance Tips

There's plenty you can do between annual services to keep your system in good shape. These aren't replacements for professional servicing — they're the between-visit basics that any homeowner can handle.

1. Keep clearance around the outdoor unit Maintain at least 5 feet (1.5 metres) of clear space around the unit. Trim back any plants, remove garden furniture, and clear away leaves and debris regularly — especially in autumn.

2. Check the system pressure Your heat pump's pressure gauge (usually on the indoor unit or cylinder) should read around 1 bar. If it drops below 0.8 bar, contact your engineer — low pressure affects performance and can indicate a leak.

3. Clean the outdoor unit Brush down the outer casing with a soft brush to remove dust, dirt, and debris. In winter, check that ice hasn't built up on the fan blades or blocked the air inlet. A thin layer of frost is normal; significant ice build-up is not.

4. Listen for unusual noises Gurgling, rattling, or grinding sounds are warning signs. Note when they occur and report them at your next service — or call your engineer sooner if the noise is persistent or getting worse.

5. Check your app or thermostat display Many modern heat pumps connect to a smartphone app and display error codes when something's off. Check it periodically, and if you see a persistent error code, look it up in your manual or contact your installer.

What Happens If You Don't Service Your Heat Pump?

Three things — and none of them are good.

1. Your warranty is voided Most heat pump manufacturers require documented annual servicing to keep the warranty valid. Miss a single year and you lose that protection, potentially leaving you liable for thousands of pounds in repair costs on a relatively new system.

2. Your energy bills go up An unserviced heat pump has to work harder to deliver the same heat output. According to Viessmann, this inefficiency can add up to 25% more electricity consumption compared to a well-maintained system. On a typical UK energy tariff, that adds up fast.

3. Your system's lifespan shortens Heat pumps are designed to last 15–20 years with proper maintenance. Small faults — a refrigerant imbalance, a blocked filter, a loose electrical connection — compound over time when left unaddressed. What would cost £30 to fix at a service can become a £600 component failure two years later.

Skipping a service to save £150–£200 is rarely the saving it appears to be.

Frequently Asked Questions About Air Source Heat Pump Servicing

How long does an air source heat pump service take?

A standard annual service takes 60 to 90 minutes. It's non-disruptive — your engineer will work on the outdoor unit and the indoor components without needing to drain the system or take your heating offline for any significant period.

Can any engineer service an air source heat pump?

No. Any engineer carrying out work that involves the refrigerant circuit must hold F-Gas certification — it's a legal requirement in the UK. For systems installed through the Boiler Upgrade Scheme, using an MCS-accredited engineer is also strongly advisable to protect your grant documentation.

Does skipping a service void my heat pump warranty?

In most cases, yes. The majority of manufacturer warranties (typically 7–10 years) explicitly require annual professional servicing with documentation. If you skip a year and something goes wrong, the manufacturer is unlikely to cover the repair. Always check your specific warranty terms and keep your service records safe.

Is heat pump servicing covered under the Boiler Upgrade Scheme?

No. The Boiler Upgrade Scheme covers the cost of installation only — up to £9,00 toward a new air source heat pump, depending on your current heating source. Annual servicing is the homeowner's ongoing responsibility. A monthly service plan (from around £10–20/month) is an affordable way to budget for it.

Keep Your Heat Pump Running at Its Best

Annual air source heat pump servicing is one of the simplest and most cost-effective things you can do as a heat pump owner. A 60–90 minute visit once a year keeps your warranty intact, your bills in check, and your system running efficiently for the long haul.

To recap:

• Service your heat pump once a year, ideally in late summer, before the winter season
• Expect to pay £150–£300 for a one-off service, or £10–20/month for a service plan
• Only use a F-Gas certified, ideally MCS-accredited engineer
• Keep your service records safe — you'll need them for warranty claims and future property sales

If you installed your heat pump through Switch Together and need a trusted engineer for your annual service, your MCS-accredited installer is on hand to help. Or if you're still weighing up whether a heat pump is right for your home, we can help with that too.