How Long Do Heat Pumps Last? Lifespan, Warranties and Replacement
An air source heat pump typically lasts 15 to 20 years, and a well-maintained system can run beyond that. Ground source heat pumps last longer because the main unit lives indoors out of the weather, and the buried ground loop can last for decades. A gas boiler, by comparison, usually manages 10 to 15 years. How long yours lasts comes down mainly to how well it was sized and installed and whether it’s serviced every year.
We install and service heat pumps across Hinckley, Leicester, Nuneaton, Coventry, Rugby and Tamworth, and the systems that give trouble early are nearly always the ones that were sized by guesswork or left without a service for several winters.
How Long Does an Air Source Heat Pump Last Compared With a Boiler?
| Heating system | Typical lifespan |
|---|---|
| Air source heat pump | 15 to 20 years |
| Ground source heat pump (indoor unit) | 20 years or more |
| Ground source heat pump ground loop | Several decades |
| Gas boiler | 10 to 15 years |
These are typical ranges rather than promises. Heat pumps fitted in the UK over the last decade are generally more reliable than earlier generations, so a modern system that’s looked after properly has every chance of reaching the top of the range.
What Affects How Long a Heat Pump Lasts?
Sizing has the biggest effect. A heat pump that’s too big for the house switches on and off constantly, known as short cycling, and every start puts wear on the compressor. One that’s too small runs flat out for long stretches. A room-by-room heat loss calculation at the design stage avoids both.
Installation quality comes next. Correctly sized pipework, a clean system with inhibitor and a magnetic filter, sound electrical connections and careful commissioning all take strain off the components. Annual servicing keeps it that way by cleaning the outdoor coil, checking pressure and filters and testing the controls before small faults grow.
How the system is run matters as well. A heat pump designed for a low flow temperature works less hard than one pushed hot to make up for undersized radiators. Where the outdoor unit sits also counts, since a unit with clear airflow, good drainage for defrost water and no leaves piling against it has an easier life than one wedged behind a bin store.
Which Parts of a Heat Pump Wear Out First?
Heat pumps rarely fail all at once. Individual parts wear and can usually be replaced on their own:
| Component | What happens | Usually repairable? |
|---|---|---|
| Circulating pump | Wears with running hours and can seize if the water is dirty | Yes |
| Outdoor fan motor | Bearings wear and become noisy | Yes |
| Sensors and controls | Temperature sensors and control boards can fail | Yes |
| Expansion vessel | Loses its charge, causing pressure problems | Yes |
| Compressor | The most expensive part; failure late in life often means replacing the unit | Sometimes, depending on age and cost |
Any work on the refrigerant circuit has to be done by an F-gas qualified engineer. When a heat pump starts losing performance, the cause is often one component that can be found and replaced before it becomes a bigger fault.
How Long Is a Heat Pump Warranty?
Manufacturer warranties on air source heat pumps vary by brand and by the installer’s accreditation, typically somewhere between 3 and 8 years. Accredited installers can often register a longer warranty than the standard one. Most warranties also depend on an annual service by a qualified engineer, so keep every service record. Workmanship is covered separately by the installer.
How Can I Make My Heat Pump Last Longer?
Book a service every year. Our article on what is included in a heat pump service lists the checks, and heat pump service costs covers what it costs. Between visits, keep the area around the outdoor unit clear of leaves, plants and snow, and leave the heat pump running steadily instead of switching it off and on, which cuts the number of compressor starts.
Keep the flow temperature as low as comfort allows, ideally with weather compensation doing the adjusting for you. Glance at the pressure gauge on the indoor unit now and then and let us know if it keeps dropping, and don’t ignore new noises or error codes. Small faults are much cheaper to fix early.
What Are the Signs a Heat Pump Needs Replacing?
A heat pump well past 15 years old that needs repairs more and more often is the classic sign. A failed compressor on an older unit is another, because the repair can cost a large share of a new heat pump. Running costs creeping up with no change in how you use the heating, a system that can no longer keep the house warm in cold weather even after a service, and parts that are no longer made for your model all point the same way.
Replacing a heat pump at the end of its life is usually simpler than the first installation, since the cylinder, radiators and pipework are already suitable and can often stay. The Boiler Upgrade Scheme can’t be used to replace an existing heat pump, so plan for replacement without a grant.
Is a Heat Pump’s Lifespan Worth Factoring Into the Cost?
Yes. Spreading the cost over 15 to 20 years rather than the 10 to 15 you’d expect from a boiler changes the sums. Our article on heat pump costs, running costs and grants sets out the upfront and running costs, and our air source heat pump pros and cons weighs lifespan against the other factors. If you already have a heat pump, our air source heat pump servicing keeps it efficient and the warranty valid.
Key Facts
- Air source heat pumps typically last 15 to 20 years.
- Gas boilers typically last 10 to 15 years.
- Ground source heat pumps last longer, and the ground loop can last for decades.
- Correct sizing, good installation and annual servicing have the biggest effect on lifespan.
- Most parts, such as pumps, fans and sensors, can be replaced individually.
- Manufacturer warranties typically run from 3 to 8 years and usually require annual servicing.
- The Boiler Upgrade Scheme can’t be used to replace an existing heat pump.