Aira vs BOXT (UK 2026): Finance + Guarantee vs Outright

Aira and BOXT are two of the largest installer-direct heat pump providers in the UK in 2026, and both sell the heat pump outright - you own it either way. The difference is what wraps around the sale. Aira offers zero-deposit finance over 5 or 10 years from 5.9% APR and an optional 15-Year Aira Guarantee that bundles servicing and repairs for £19.90/month after a free first year (Aira, October 2026). BOXT sells a fixed-price Vaillant install with optional finance, and servicing is arranged separately. This comparison covers the cost, the cover and what happens at house sale.

Earlier versions of this page described Aira as a subscription in which Aira owns the hardware. As of October 2026 Aira's UK pages do not offer that: Aira sells purchase plus finance, and the guarantee is the only optional monthly charge.

The honest comparison models the full ownership horizon, not just the install cost. Aira publishes a representative example (typical 2-bed terrace, 6 kW Aira Heat Pump, £8,200 purchase price); the BOXT figures below are for a typical 3-bed UK semi, so read the two as orders of magnitude rather than like-for-like quotes.

Aira, paid up front: £8,200 + the guarantee at £19.90/month for years 2-15 (£3,343) = £11,543 over 15 years, including servicing, parts and labour while the guarantee runs.

Aira on finance: 5 years at 5.9% APR is £158.15/month (£9,489 in total); 10 years at 9.9% APR is £107.91/month (£12,949). Adding the guarantee gives £12,832 or £16,292 over 15 years (Aira, October 2026).

BOXT outright + finance: £8,500 post-grant install cost (£14,500 install − £7,500 BUS − £1,500 0% finance vs cash discount adjustment) + £200/year annual service × 15 = £11,500 + estimated £1,500 in repair costs over 15 years (~£100/year average) = £13,000 total over 15 years. As with Aira, you own the asset at year 15 with some residual value (£500-£1,500 in scrap + remaining warranty if any).

Paid up front, Aira's example comes out below BOXT's typical figure, but it is for a smaller home; on 10-year finance it costs more. The cash-flow profiles differ too: Aira on 10-year finance is about £128/month in years 2-10 (repayment plus guarantee) and £19.90/month in years 11-15, against BOXT's £140-£200/month for years 1-5 (during 0% finance) and ~£20/month equivalent (annual service + repair reserve) for years 6-15.

Both providers apply the £7,500 Boiler Upgrade Scheme grant to your quote:

BOXT: the grant appears as a discrete line on your install quote - £14,500 gross cost minus £7,500 BUS = £7,000 net cost (plus VAT relief). BOXT applies the grant on your behalf at the install stage; you see the deduction directly. If you finance the install, the finance amount is the net post-grant figure.

Aira: Aira applies for the grant on your behalf and deducts it from your invoice, so your quote already shows the post-grant price (Aira, October 2026).

Both routes use the grant the same way and pass its full value to you.

Both routes leave you owning the heat pump, so it transfers with the house as a fixture.

BOXT outright: you own the heat pump. At house sale, it transfers with the house as a fixture. The remaining manufacturer warranty (typically 5-7 years for Vaillant) transfers to the new owner. The heat pump may add £2,000-£5,000 to the home's sale price as a documented MCS-certified efficient heating system.

Aira: the heat pump is also yours. Two things need settling at sale: any outstanding Aira finance, which is repaid under your credit agreement (early repayment is available), and the 15-Year Aira Guarantee, which has its own rules for transferring to a new owner. Check both before you commit if you might move within the guarantee's term.

Pick Aira if: you want a single provider for survey, install and up to 15 years of cover, you'd rather spread the cost with no deposit, you expect to stay in the property long enough for the guarantee to pay its way, and you value the "no bill shock" servicing model.

Pick BOXT outright if: you have £6,000-£10,000 available (cash, 0% finance, or equity release), you want lower ongoing costs, you're confident managing service contracts and out-of-warranty repairs yourself, or you may sell the house within 10 years.

The choice is less about ownership - you own the heat pump either way - and more about how much long-term cover you want to buy and what interest rate you'll pay to spread the cost. Compare Aira's 5.9-9.9% APR with any 0% offer before deciding.