Heat pump servicing and lifespan: what a landlord needs to plan for

The short answer

A heat pump in a rental needs an annual service, not an annual safety certificate. The Energy Saving Trust (EST) says to service it according to the manufacturer’s advice, usually once a year, like a gas or oil boiler, and gives a typical cost of around £150. It says the heat pump itself is likely to last 20 years or more. For a landlord, that means a predictable yearly cost, a few legal points that are easy to miss, and one practical job: getting the engineer and the tenant in the same place.

What a heat pump service covers

The EST lists what an air source heat pump service typically involves:

• an electrical safety check
• checking the thermostat works
• a general visual inspection of the unit
• checking for leaks and pressures, and refilling refrigerant if needed
• cleaning filters and coils
• checking the large components, such as the compressor, fan and pump
• lubricating moving parts
• replacing small parts such as seals and gaskets, as the manufacturer specifies

For a ground source heat pump, the EST adds checks on the ground loop: antifreeze concentration, flow and return temperatures, and pressure.

Ask the engineer to also look at the settings. Performance problems, the EST says, usually come from the way the system is set up and used rather than equipment failure, so a check on flow temperature, schedules and the hot water cycle is often worth more to your tenant’s bill than any part. Write the settings down for the next tenant.

What it costs, and what moves the price

The EST says costs for heat pump servicing vary with the type of heat pump, and that you can typically expect to pay around £150. That is the only service price this guide quotes, because it comes from an official adviser. Your quote will move with:

• the type: ground source work includes the loop checks above
• the size and number of units, including any separate cylinder or buffer tank
• whether refrigerant work, parts or a leak test are needed
• travel, particularly for rural properties
• whether you book a one-off visit or a plan that includes call-outs

Ask whether the price includes a written report, which you will want for your records and for any warranty claim.

There is no annual safety certificate, but there are duties

A gas boiler in a rental brings a fixed legal routine. The Gas Safety (Installation and Use) Regulations 1998 require a landlord to have each gas appliance and flue checked at least every 12 months and to keep a record, with a copy to the tenant within 28 days. That duty attaches to gas appliances. This guide found no comparable annual statutory safety record for a heat pump.

That does not mean no duties apply:

• Repair. Under section 11 of the Landlord and Tenant Act 1985, most tenancies in England carry the landlord’s duty to keep the installations for space heating and heating water in repair and proper working order. In Wales, occupation contracts under the Renting Homes (Wales) Act 2016 have their own repair rules.
• Electrical safety. The fixed electrical installation needs inspecting at least every 5 years in England, with remedial work within 28 days and penalties of up to £40,000.
• F gas. Some heat pumps need periodic leak checks by law, depending on the refrigerant and how much of it the unit holds. See the next section.

If you are switching from gas, read what happens to the gas safety certificate, because a gas hob or fire left in place keeps the annual check alive.

F gas leak checks: the thresholds

Many heat pumps use a fluorinated refrigerant, an F gas. GOV.UK guidance on checking F gas equipment for leaks lists stationary heat pumps among the equipment covered, and sets the frequency by the charge measured in tonnes of carbon dioxide equivalent:

F gas charge (tonnes CO2 equivalent)	Leak check at least every
Below 5	No frequency set in the guidance
5 to less than 50	12 months
50 to less than 500	6 months
500 or more	3 months, and a leak detection system is required

Two adjustments apply. Where a leak detection system is fitted, the guidance doubles the checking period, so equipment from 5 to less than 50 tonnes is checked every 2 years. For hermetically sealed refrigeration and air conditioning systems, the guidance sets no maximum period between checks unless they contain the equivalent of 10 tonnes of carbon dioxide or more.

The conversion depends on the gas. The guidance gives 2.4kg of R410A as the amount equal to 5 tonnes. Do not guess where your unit sits: ask the installer, in writing, which refrigerant the unit uses, its charge in kg and in tonnes CO2 equivalent, and whether any leak check applies. Keep the answer with the commissioning papers, and ask that any refrigerant work is done by an engineer with an F gas qualification.

Warranties: why the service record matters

There are usually two layers of cover, and servicing affects the first.

The manufacturer’s warranty covers the equipment. Its terms decide how long it lasts, whether it needs registering, how often the unit must be serviced and who may service it. If the terms require an annual service by an approved engineer, a missed year can give the manufacturer grounds to refuse a claim. Read the terms at handover, register the product if required, and diarise the service.

The installer’s workmanship guarantee covers the installation. MCS tells its certified installers that for domestic customers they must guarantee the workmanship for at least two years, that the guarantee must transfer to a new owner if the property is sold, and that it must be protected so it is honoured if the installer stops trading. Check the installer is certified on the MCS register before you sign; the Boiler Upgrade Scheme requires an MCS certified installer anyway.

The EST’s advice to people buying a home with a heat pump is to ask for the warranty and the service record. A future buyer of your rental may ask the same, so a complete file is worth keeping.

Access: arranging the visit with your tenant

Servicing a heat pump in a let property means agreeing access. In England, a lease covered by section 11 also implies that the landlord, or someone authorised in writing, may enter at reasonable times of day to view the condition of the property, on 24 hours’ notice in writing to the occupier. In practice it is easier to agree a date with the tenant than to rely on that notice, and the tenancy agreement may have its own access clause.

A simple routine:

1. Book the service for the same month each year, outside the coldest weeks.
2. Write to the tenant with two date options and who is coming.
3. Ask the tenant to keep the outdoor unit clear. The EST mentions bikes, wheelie bins and leaves as the usual obstructions.
4. Ask the engineer for a written report and file it with the warranty papers.
5. Note any setting changes in the tenant’s handover sheet.

Put the tenant’s part in writing at the start of the tenancy: what to keep clear, what is normal noise and frost-clearing behaviour, and who to call. The running costs guide lists what a handover note should include.

Lifespan and budgeting

The EST says that once installed correctly you are not likely to see much in the way of equipment failure, and that the heat pump itself is likely to last 20 years or more, longer than the average gas or oil boiler. Treat that as a guide, not a guarantee for any one unit.

Worked example (modelled, not a real project)

Inputs, all stated:

• Annual service at the EST’s typical figure: £150 (today’s price, no inflation applied)
• Life of the heat pump: 20 years, the EST’s lower figure
• Installed cost: around £12,000, the EST’s typical price for an air source heat pump, less the £7,500 Boiler Upgrade Scheme grant, leaving £4,500

Results:

• Servicing over 20 years: 20 × £150 = £3,000
• Net installed cost spread over 20 years: £4,500 ÷ 20 = £225 a year
• Together: £225 + £150 = £375 a year, before repairs, parts and price rises

This leaves out repairs because no official source gives a figure. Keep a contingency for repairs to other parts of the system, which this sum does not cover.

When servicing is not your biggest risk

A perfect service record will not fix a system that was badly designed. If the tenant reports high bills or cold rooms in the first winter, the cause is more likely to be sizing, radiators or settings than wear. Go back to the installer under the workmanship guarantee first. And if you have not installed yet, the strongest protection is a proper heat loss calculation and a clear handover, covered in the pre-installation checklist.

Next step

To see how upkeep fits the overall numbers, use the landlord heat pump calculator. If you want prices, send an enquiry and relevant independent firms contact you, with no charge to you and no obligation.