Best Heat Pump Installers UK 2026: Honest Comparison

Picking the best [heat pump](/blog/heat-pump-cost-uk-2026/) installer in the UK in 2026 is harder than it should be. The same property routinely receives quotes that vary by £4,000–£6,000 between MCS-certified installers, and headline pricing — including Octopus Energy's banned "as low as £500" claim, which only 5.8% of installs actually met — has trained UK consumers to mistrust the published numbers. This guide compares the named installers people actually consider in 2026: [BOXT](/review/boxt-heat-pump-review/), Heatable, Octopus Energy, [Aira](/review/aira-heat-pump-review/), the Heat Geek network, and iHeat. The framing is factual, sourced from each company's published terms and the Microgeneration Certification Scheme (MCS) consumer record — not editorial opinion.

Six criteria drive the rankings below, in order of weight:

1. MCS certification status. A non-negotiable. The Boiler Upgrade Scheme (BUS) — the £7,500 grant in England and Wales, rising to £9,000 from July 2026 for oil and LPG-heated homes — is only available through an MCS-certified installer. You can verify any installer's accreditation directly via the MCS Installer Database before signing anything.
2. Coverage area. Octopus Energy in particular declines leads in some regions (Scotland outside the central belt is a recurring gap), and brand-name installers don't always cover rural England. The MCS Data Dashboard is the most reliable way to check who actually installs near you.
3. Pricing model. Fixed-price installers (BOXT, Heatable, Octopus on simple properties) commit to a price after a remote survey; survey-led installers (Heat Geek network, most independent MCS firms) only price after a property visit. Fixed-price is faster but trades flexibility — Octopus, for example, has a documented pattern of refusing radiator-sizing tweaks that improve flow temperature.
4. Warranty terms. Aira's 15-year "Comfort Guarantee" is the longest in-market — five years longer than its closest UK rival. Most other installers track the manufacturer's warranty (Vaillant 7 years, Daikin 7 years, Mitsubishi 7 years) plus a 2-year workmanship guarantee.
5. BUS handling. Some installers process the BUS application on your behalf and net it off the quoted price; others leave the application to you. Net-off pricing is faster but the headline figure isn't comparable to a pre-grant quote.
6. Public review data. Trustpilot scores in this niche skew positive — five of the six installers below sit at 4.7 or higher. Read scores in context: a 4.9 across 10,000 reviews carries more signal than a 4.9 across 80 reviews, and review volume on a heat pump installer is itself a coverage proxy.

BOXT is the UK's highest-volume MCS-certified installer for both boilers and heat pumps. Its primary heat pump partnership is with Vaillant — most BOXT heat pump installs are an aroTHERM Plus paired with a Vaillant-branded cylinder. The pricing model is fixed-price after a remote survey: BOXT publishes an indicative quote based on property type, EPC, and current heating system, then confirms the price post-survey.

BOXT processes the £7,500 BUS grant on your behalf and nets it off the quote. Coverage is strongest across England with partial Welsh coverage; you can confirm availability for your postcode on BOXT's site before going further. The Vaillant warranty runs to 7 years on the heat pump itself, with BOXT's own 2-year workmanship guarantee covering the install.

BOXT's public review record sits around 4.7/5 on Trustpilot across more than 58,000 reviews — high volume, broadly positive, with the usual mix of post-warranty complaints any volume installer accumulates. Where BOXT is the wrong choice: properties that need atypical hardware (R290 propane refrigerant units other than aroTHERM Plus, larger 16+ kW systems, or ground-source rather than air-source), and homes outside its coverage map.

Heatable operates a network model: it sources homeowner leads, qualifies them remotely, and books an MCS-certified network installer to carry out the install. It runs across boilers, solar and heat pumps, and is Gas Safe registered for the gas side and MCS certified for renewables.

Heatable's combined Trustpilot, Google and Reviews.io data shows a ~4.9 average across more than 10,000 5-star reviews — the highest cross-platform aggregate of the named UK installers. Hardware varies depending on the network installer assigned: Vaillant, Daikin and Mitsubishi all appear regularly. BUS is netted off the quoted price.

The trade-off with a network model is consistency: the brand is fixed but the install team is local, so commissioning quality and aftercare scale with the individual firm assigned. Heatable's vetting is the proxy for that, but a homeowner can also cross-check the assigned firm's MCS record once the network match is made.

Octopus Energy Services is the install arm of Octopus Energy. Its primary install hardware is the Octopus Cosy 6 (covered in our [Octopus Cosy 6 review](/review/octopus-cosy-6-review/)), an own-brand 6 kW air-source heat pump aimed at the typical UK 3-bed property. Octopus also historically installed Daikin units on properties not suited to the Cosy 6.

Octopus's selling point is price. Trustpilot rating sits at 4.8/5 and the company has been the most aggressive on headline pricing — including the "as low as £500" advertising banned by the Advertising Standards Authority in 2025 after Octopus disclosed that only 5.8% of installations actually met that price. The realistic post-BUS price for most properties is in the £4,500–£7,500 band, with sub-£1,000 outcomes reserved for well-insulated modern homes that take a 5 kW unit off-the-shelf.

Two limits worth flagging. First, Octopus declines leads in regions outside its install coverage rather than forwarding them to its Trusted Partner network by default — Edinburgh and parts of Scotland are a recurring gap. Second, Octopus's fixed-price model is rigid on hardware and design changes: the Cosy 6 or a Daikin alternative are typically the only options offered, and quote requests for radiator-sizing changes that would improve seasonal performance are sometimes declined.

If Octopus cannot serve you, the right next step is the Octopus Trusted Partners programme (covered below) — not abandoning Octopus's hardware preference, just routing through a vetted external installer.

Aira is the UK arm of a Swedish manufacturer-installer that fits only its own-brand air-source heat pump. Two things differentiate it: the warranty and the financing.

The warranty is a 15-year "Comfort Guarantee" — five years longer than its closest UK rival's term. It bundles 10 years of free annual servicing (otherwise priced around £20/month), which materially shifts the total-cost-of-ownership calculation against shorter-warranty competitors.

The financing is the genuine novelty. Aira offers a subscription-style finance plan that spreads the post-BUS install cost over monthly payments — typically £50–£100/month over 15 years. There's no zero-cash-down equivalent from any other UK heat pump installer in 2026. The trade-off is total spend: a fully-financed Aira install will cost more across 15 years than a one-off cash-or-loan purchase of an equivalent system from a volume installer, in exchange for warranty length, included servicing, and no up-front capital.

Pricing on the cash side is mid-to-premium. The same property recently received an Aira quote of around £12,000 alongside an Octopus quote of £6,200 and a Heat Geek installer quote of £7,350, although Aira pricing is reportedly negotiable down toward £8,000–£9,000 in many cases. Aira does not have a public CPS affiliate programme — partner discount routes are direct only.

Heat Geek is structurally different from the others on this list. Rather than installing directly, it operates a vetted network of independent MCS-certified installers who have passed Heat Geek's own design and commissioning training. The pitch is engineering quality: lower flow temperatures, higher SCOP (Seasonal Coefficient of Performance), and a performance guarantee on top of the manufacturer's hardware warranty.

The Heat Geek network is the named "premier partner for heat pump installs" in the Octopus Trusted Partners programme — Heat Geek installers automatically receive Octopus referrals in regions Octopus itself can't serve. Independent rating from Which? sits near 5/5.

Pricing tends to run higher than fixed-price competitors for two reasons: design time (a Heat Geek install includes a property-specific heat-loss calculation and radiator sizing review) and the use of higher-spec hardware where it improves long-term efficiency. The argument for the premium is running cost, not install cost — a lower flow temperature means a higher SCOP, which means lower electricity use over the system's life.

If you're comfortable paying more upfront for a higher-efficiency design, Heat Geek is the strongest option in this list. If you have a simple property with a clean retrofit path, the savings from a fixed-price installer may outweigh the running-cost gap.

iHeat is an online-first network installer focused on remote-quote workflows. Hardware is typically Vaillant or Daikin via partner installers; coverage is England and Wales. Trustpilot rating sits around 4.8/5. iHeat's BUS handling and warranty terms track the volume-installer pattern: net-off pricing, manufacturer warranty plus 2-year workmanship.

iHeat's strongest fit is homeowners who want a fast remote quote without a sales-led survey. The trade-off is the same network-model variance as Heatable: the assigned installer's individual quality drives the experience more than the brand on the website.

The named installers above are not the only route. Around 2,500 individual MCS-certified installer firms operate across the UK as of 2026, most without a national consumer brand — and BUS-eligible installs through any of them go through the same scheme on the same terms.

The starting point is the MCS Data Dashboard, the public consumer-facing tool that lists every accredited installer by postcode with their certification scope (air-source, ground-source, or both) and current accreditation status. Filter by your postcode, cross-check each candidate against Trustpilot or Checkatrade, and request site-survey quotes from at least three.

Two consumer-protection bodies sit alongside MCS: HIES (Home Insulation and Energy Systems Quality Assured Contractors Scheme) and RECC (Renewable Energy Consumer Code). Both provide a complaints and redress mechanism if an MCS install goes wrong. Octopus Trusted Partners are required to belong to one of them; for off-brand installers, ask which they're aligned with before signing.

Every installer named here processes the £7,500 Boiler Upgrade Scheme grant on the homeowner's behalf and nets it off the quoted price. The scheme is administered by Ofgem and runs through the MCS-certification supply chain — a non-MCS installer cannot access it.

From July 2026, the BUS grant rises to £9,000 for homes currently heated by oil or LPG, subject to formal Ofgem notice (covered in our [BUS oil and LPG guide](/blog/bus-9000-oil-lpg-grant/)). If your property currently uses oil or LPG, waiting for the higher grant is worth modelling against the running-cost benefit of switching sooner.

BUS guidance v5 has been in force since 28 April 2026 (covered in our [BUS v5 guide](/blog/bus-guidance-v5-changes/)). The most material change for installer selection is the EPC rating requirement removal — properties that previously fell out of scope on EPC grounds may now qualify, depending on the installer's reading of the new guidance.

Five of the six installers above sit at 4.7 or higher on Trustpilot. That isn't because UK heat pump installation is uniformly excellent — it's because Trustpilot reviews skew toward customers whose installs went smoothly and who were prompted to leave a review at the post-install handover.

Two adjustments make Trustpilot more useful for this decision. First, weight by review volume: 10,000+ reviews behind a 4.9 carries far more signal than 80 reviews behind the same score. Second, read the negative reviews specifically — what failure modes recur? In this niche the recurring patterns are: long install lead times (commissioning over months rather than weeks), aftercare slowness (one prominent case described a 7-month commissioning saga), and disagreements over whether radiators or pipework needed replacing.

None of those recurring patterns means a given installer is the wrong choice — they're industry-wide. They do mean it's worth asking each shortlisted installer how they handle each of them before signing.

If you have a typical 3-bed property in England with a clean retrofit path and you want the cheapest competent install, Octopus Energy and BOXT are the two strongest fixed-price options — Octopus on the Cosy 6, BOXT on Vaillant. If you want the longest warranty and the option to spread cost monthly with no up-front cash, Aira's subscription model is unique in the UK market. If you're willing to pay more upfront for a higher-efficiency design and lower long-term running cost, a Heat Geek network installer is the strongest design-led option. And if none of the named installers cover your area, the MCS Data Dashboard is the consumer-facing route to local accredited firms — held to the same scheme, on the same terms, with the same BUS access.

Whichever route you pick, get three quotes, verify MCS scope on every one, ask for the heat-loss calculation, and check BUS handling is netted off. Those four checks are the difference between a confident decision and a leap of faith.