Buying advice

Boiler finance explained: 0%, pay monthly, or upfront?

A new boiler is £2,500 on average — more than most people want to put on a credit card. So installers offer finance. Here's what the different plans actually cost, when 0% genuinely is 0%, and the question nobody asks: is the cash-price quote still the same if you take finance?

The three finance types

0% APR (2–3 years)

Best

You pay the boiler off in equal monthly installments over 24 or 36 months. Total cost = sticker price. No interest.

Typical: £2,500 boiler ÷ 36 months = £69/month. Total paid: £2,500.

Actually free money — if you'd have paid cash anyway, put the £2,500 in a high-interest savings account and earn ~5% while the installer absorbs the finance cost.

Buy Now Pay Later (deferred)

Careful

Pay nothing for 6–12 months, then pay in full or convert to monthly. If you pay before the deferred period ends, zero interest. Miss the deadline by a day and interest backdates to day one at rates up to 20%.

Typical catch: 11-month deferred period, then interest at 19.9% APR applies to the full balance backdated.

Fine if you have a clear plan to pay off in full. Dangerous if you "plan to figure it out later."

Extended finance (5–10 years)

Expensive

Monthly payments as low as £35–£45, but interest rates of 9.9–14.9% APR. Total paid can be £4,000–£5,500 on a £2,500 boiler.

Typical: £2,500 boiler over 10 years at 11.9% APR = £37/month. Total paid: £4,460.

Avoid unless you genuinely can't stretch to the 0% option. In that case a credit union or 0% purchase credit card can be cheaper.

The key question nobody asks

"What's your cash-buyer price?" Some installers will knock 3–5% off for cash upfront because they save the finance-broker fee. If you're a cash buyer, always ask for this discount — worst case they say no, best case you save £100–£200.

What you'll need to qualify

› UK resident, 18+
› Proof of ID + address
› Income (most lenders ask for £15,000+ annual)
› Soft credit check (doesn't affect credit score)
› Hard search if you proceed — small credit score impact, recovers in 3–6 months

Most online installers (Boxt, Heatable, iHeat) pre-approve you during the online quote — no obligation.