Heat Pump Warranties Compared: What Every UK Buyer Should Check

Understanding your heat pump warranty UK options is one of the most important steps before committing to a purchase. A heat pump is a significant investment, typically costing between £10,000 and £16,000 after the Boiler Upgrade Scheme grant, and the warranty backing that investment can vary enormously between manufacturers. Getting this wrong could leave you facing repair bills of £2,000 or more with no cover in place.

Heat Pump Warranties Compared: UK Brands

Always check what is actually covered — most heat pump warranties cover the compressor and refrigerant circuit but exclude ancillary components like the controller, circulation pump or hot water cylinder. Extended warranties typically require annual professional servicing, so factor in £100–£180 per year for maintenance when comparing total ownership costs.

This guide compares the warranty terms offered by the five most popular heat pump brands installed in UK homes, explains the conditions that can void your cover, and highlights what to look for before you sign on the dotted line.

Why Heat Pump Warranty Terms Matter More Than You Think

Unlike a gas boiler that might last 12-15 years, a well-maintained heat pump should operate for 20-25 years. That longer lifespan means warranty terms carry even greater significance. A compressor replacement alone can cost £1,500-£3,500 depending on the model, and a full refrigerant circuit repair can exceed £2,500.

Most manufacturers split their warranty into two parts: the main unit warranty and an extended compressor warranty. The compressor is the heart of the system, and because it runs continuously during the heating season, it faces the most wear. Understanding exactly what each warranty covers, and critically what it excludes, could save you thousands over the lifetime of your system.

If you are exploring your options, our heat pump product page provides a useful starting point for understanding the different systems available.

Heat Pump Warranty Comparison: Brand by Brand

Below is a detailed breakdown of the warranty terms offered by the five leading heat pump manufacturers in the UK market as of 2026.

Vaillant aroTHERM Plus

Vaillant offers a standard 7-year warranty on the aroTHERM plus range when installed by a Vaillant Advance installer. The warranty covers parts and labour for manufacturing defects and component failures. Vaillant requires annual servicing by a qualified engineer to maintain cover, and the system must be registered within 30 days of commissioning. Without Advance installer registration, the standard warranty drops to just 2 years.

Grant Aerona3

Grant provides a 7-year parts and labour warranty on the Aerona3 range, one of the most generous standard offerings in the UK market. The warranty covers the compressor, all internal components, and the controller. Grant requires annual servicing and registration through the Grant Installer Network. The Aerona3 is manufactured in Ireland, which means spare parts availability tends to be quicker than for some Asian-manufactured units.

Daikin Altherma

Daikin stands out with the longest available warranty in the UK market. The standard warranty is 5 years, but this can be extended to up to 12 years when installed by a Daikin Sustainable Home installer and registered through their D1+ platform. The extended warranty requires an annual service contract, and Daikin offers their own maintenance plans starting from around £180 per year. The 12-year option provides exceptional peace of mind but does come with higher ongoing service costs.

Mitsubishi Ecodan

Mitsubishi takes a slightly different approach with a 3-year standard warranty that can be extended by an additional 4 years (7 years total) when installed by a Mitsubishi Approved installer. The compressor itself carries a separate 5-year warranty as standard. The extension must be applied for within 3 months of installation. Mitsubishi also requires annual servicing, and their MELCloud smart monitoring system can flag faults early, potentially preventing warranty claims altogether.

Samsung EHS Mono

Samsung offers a 7-year warranty on the EHS Mono range, covering the outdoor unit, compressor, and indoor hydro unit. Samsung has rapidly grown its UK market share since 2023 and backs this with a dedicated UK service team. Annual servicing is required, and the system must be installed by an MCS-certified installer. Samsung’s warranty is notable for including the controller and all ancillary components as standard.

Heat Pump Warranty UK: Side-by-Side Comparison Table

What Can Void Your Heat Pump Warranty?

The single most common reason for voided heat pump warranties in the UK is missed annual servicing. Every major manufacturer requires proof of annual maintenance by a qualified engineer. Miss a single year and you could lose all remaining cover, even if the fault has nothing to do with servicing.

Beyond servicing, the following actions or omissions will typically void your warranty:

• Installation by a non-approved installer – Most extended warranties require installation by the manufacturer’s accredited network
• Late registration – Failing to register the installation within the required window (usually 30 days)
• Incorrect system design – Undersized or oversized systems, incorrect pipework, or inadequate buffer tanks
• Non-approved refrigerant top-ups – Only F-Gas certified engineers should handle refrigerant
• Power supply issues – Voltage spikes or incorrect electrical supply not covered
• Modifications to the system – Unauthorised changes to controls, pipework, or refrigerant circuits
• Limescale damage – Some manufacturers exclude damage in hard water areas without appropriate treatment

It is worth noting that general wear and tear items such as filters, expansion vessels, and external casing cosmetic damage are typically excluded from all warranties.

Annual Servicing: The Non-Negotiable Warranty Requirement

A heat pump service typically costs between £100 and £200 per year, depending on your location and the complexity of the system. While this might seem like an unwelcome ongoing cost, it is essential for maintaining your warranty and, more importantly, for keeping the system running at peak efficiency.

During an annual service, a qualified engineer will typically check:

• Refrigerant pressures and temperatures
• Electrical connections and component integrity
• Heat exchanger condition and cleaning
• System pressures and flow rates
• Controller settings and error logs
• External unit condition, including coil cleaning
• Safety device operation

Some manufacturers, such as Daikin, offer their own service contracts that bundle the annual service with the extended warranty. While these tend to cost more than independent servicing (around £180-£250 per year), they guarantee that the service meets the manufacturer’s exact specification and remove any ambiguity about warranty validity.

How to Maximise Your Heat Pump Warranty Protection

Taking a few simple steps at the point of purchase and installation can dramatically improve your warranty protection:

• Choose an approved installer – Always use the manufacturer’s accredited installer network to qualify for extended warranty terms
• Register immediately – Do not wait; register the installation within the first week if possible
• Keep all documentation – Store your commissioning certificate, MCS certificate, and service records safely
• Set annual service reminders – Book your service well before the anniversary date to avoid lapses
• Use genuine parts – If any repairs are needed outside warranty, use manufacturer-approved components
• Monitor system performance – Most modern heat pumps have apps or monitoring systems; use them to spot issues early

Pairing your heat pump with proper home insulation also reduces the workload on the system, which in turn reduces the likelihood of component failure and warranty claims.

Beyond the Manufacturer: Additional Protection Options

If you want protection beyond the manufacturer’s warranty period, several options exist. Home emergency insurance policies from providers like British Gas HomeCare and HomeServe now include heat pump cover, though premiums tend to be higher than for gas boiler cover, typically £25-£40 per month.

The MCS consumer code also provides a degree of protection. All MCS-certified installations come with membership of either the RECC or HIES consumer protection scheme, which provides an insurance-backed guarantee typically lasting 2 years. This covers you if the installation company ceases trading.

For those who want maximum peace of mind, some installers offer their own extended warranty packages on top of the manufacturer’s cover. These can extend total protection to 15 years or more, though you should always check the underwriter and claims process before committing.

Ready to explore heat pump options with full warranty protection? Get a free quote from our network of MCS-certified installers.

Frequently Asked Questions

What is the longest heat pump warranty available in the UK?

Daikin currently offers the longest warranty at up to 12 years when installed by a D1+ registered Sustainable Home installer with an ongoing service contract. Grant and Samsung both offer strong 7-year standard warranties without needing an extended plan.

Will my heat pump warranty be void if I miss one annual service?

In most cases, yes. All five major manufacturers require annual servicing as a condition of warranty cover. Missing even a single service can void the remaining warranty period entirely. Always book your service before the anniversary date and keep proof of the completed work.

Does the BUS grant affect my heat pump warranty?

The Boiler Upgrade Scheme grant does not directly affect your warranty, but it does require MCS-certified installation, which in turn typically qualifies you for the manufacturer’s full warranty terms. The grant essentially ensures you meet the installation standards that warranties demand.

Can I service my own heat pump to maintain the warranty?

No. All manufacturers require servicing by a qualified engineer, and any work involving the refrigerant circuit must be carried out by an F-Gas certified technician. Self-servicing will void your warranty. You can, however, carry out basic maintenance such as cleaning debris from the outdoor unit and checking filters between professional services.

What happens if my heat pump installer goes out of business during the warranty period?

Your manufacturer warranty remains valid regardless of the installer’s status, provided the installation was properly registered and servicing has been maintained. The MCS consumer protection scheme (via RECC or HIES) provides an additional insurance-backed guarantee covering the installation workmanship for at least 2 years.