Interest Free Boiler or Free ECO4 Grant? How Boiler Finance Compares

An interest free boiler deal is a finance agreement: a lender spreads the price over a set term at 0% interest, so you still repay the full cost, usually after a credit check. A free ECO4 grant is a different route: energy suppliers fund eligible work for qualifying households, so a household may pay nothing for fully funded work, but a contribution or no award at all is possible. This guide compares the two, explains how boiler finance works and says who should check ECO4 first. Apply Free Boiler is run by Reliant Energy Solutions Ltd, an ECO4 installer. We do not offer finance and are not a lender, the government, Ofgem, British Gas or an energy supplier.

Interest-free boiler finance is not a free ECO4 grant

Search results for “interest free boiler” are dominated by retailer, manufacturer, and installer pages offering pay-monthly or 0% promotional credit. That is a consumer finance pathway: you agree to repay the cost of the boiler (and any agreed charges) under the lender’s terms, usually after a credit check.

ECO4 (Energy Company Obligation) is different. It is a Great Britain obligation scheme under which larger energy suppliers fund eligible energy-efficiency measures for qualifying households after assessment — not a shop checkout loan. Ofgem describes ECO as a supplier obligation, not a cash grant you spend yourself. When a measure is fully funded under scheme rules, the household may not pay for that funded work — but contributions, alternative measures, or no award at all are all possible after a survey.

Primary scheme context: GOV.UK Energy Company Obligation , Ofgem ECO consumer support . For how the scheme works on this site, see our ECO4 scheme guide.

Can you get a boiler on finance? How interest free boiler deals work

Yes. Many retailers, manufacturers and installers advertise boiler finance, and some promote 0% deals. It is borrowing, not help with the price: you spread the cost of the boiler over a term and repay it in full.

• Searches such as “new boiler interest free”, “interest free boiler deals” and “interest free boiler finance” mostly lead to these credit offers, not to grants.
• “0%” describes the interest rate on the agreement. The boiler price, any deposit and any fees in the agreement still count towards what you pay.
• Read what happens if you miss a payment or if a promotional period ends before you read the headline rate.

Apply Free Boiler does not offer or arrange boiler finance, so we cannot compare lenders or tell you which agreement suits you. This page is general information, not financial advice.

What “interest free boiler” ads usually mean

In UK commercial search, “interest free boiler” almost always means one of: pay-monthly boiler packages, 0% APR for a limited period, manufacturer-backed finance, or installer “buy now, pay later” style credit. Creditworthiness, deposit expectations, and what happens when a promotional 0% window ends all depend on the live agreement — we do not quote specific APRs, products, or lender names as endorsements here.

• “Interest free” ≠ “nothing to pay forever.” You are still entering a credit agreement for the boiler and installation cost unless a separate funded grant route applies.
• Ads may sit next to words like “free” or “grant” in the same landing page — read whether the small print is finance, not ECO4.

If the headline feels like a government grant, use our free boiler grant scam guide before you sign anything.

Pay monthly boiler plans: credit checks, total cost and FCA lenders

A pay monthly boiler plan is a credit agreement. Expect a credit and affordability check, compare the total you would repay, and check the lender is authorised by the FCA before you sign.

• Credit and affordability checks. Lenders check whether you can afford to repay before they lend; the FCA says this is required for the regulated deferred payment credit described below. Ask whether the lender will run a soft or a hard search on your credit file before you apply.
• Total cost. Multiply the monthly payment by the number of months, then add any deposit and fees. Compare that with a cash quote for the same boiler and installation, and judge the monthly figure against what you can comfortably afford.
• FCA-authorised lender. From 15 July 2026 the FCA regulates deferred payment credit: interest-free credit repayable in 12 or fewer instalments, where the lender and the supplier are different firms. Agreements made before that date stay unregulated. Whatever the term, look the lender up on the FCA Firm Checker . The FCA says to avoid a firm that is not authorised or lacks permission, and that using one means no access to the Financial Ombudsman Service or the Financial Services Compensation Scheme.

Further reading: FCA guide to buy now pay later and MoneyHelper on buy now pay later .

How much does a new boiler cost to fit?

There is no single average that fits every home. The cost depends on the boiler type, the size of the home, the work needed on the existing system and the installer’s quote.

Get written, itemised quotes from more than one installer, then compare the cash price with the total repayable on any finance. We do not quote prices here; the Energy Saving Trust boiler guide is a good starting point for typical costs.

Interest-free finance vs an ECO4 funded boiler: side-by-side

The “free boiler” name people search for maps to ECO4; our free boiler scheme guide explains how. Neither column guarantees a new gas combi — surveys and scheme rules decide measures.

British Gas and other “interest free boiler” offers

Large energy retailers and national installers often appear on finance SERPs with “ways to pay” or 0% boiler pages. That is separate from Help to Heat / ECO4 eligibility — and separate from the popular “British Gas free boiler scheme” grant myth. We do not claim exclusive partnerships with any supplier and we do not list live finance SKUs; read the retailer or lender terms on the day you apply.

For supplier free-boiler confusion (not finance brochures), see our British Gas free boiler scheme vs ECO4 guide. Apply Free Boiler is not British Gas and does not arrange their finance products.

Who should check ECO4 first, before taking boiler finance

If you receive a Help to Heat benefit, Pension Credit, live on a low income that may qualify for LA Flex, or heat an inefficient home, a free ECO4 eligibility check may be worth doing before you sign boiler finance — funding is never guaranteed, but you avoid locking into credit while a scheme route might still be open.

Ofgem says households usually qualify by receiving a listed benefit or through a local authority ECO4 Flex referral; our LA Flex scheme guide covers the council route. Per GOV.UK, the home also needs a low enough EPC band, which differs for owner-occupiers and private tenants. Our free boiler scheme guide explains how the routes fit together.

• Free boilers for pensioners & Pension Credit
• LA Flex without benefits (Statement of Intent)
• Warm Homes Local Grant vs ECO4

Finance SERPs sometimes mention heat pumps alongside gas boilers; the Boiler Upgrade Scheme on GOV.UK is a separate clean-heat grant pathway with its own rules. GOV.UK says it covers heat pumps and biomass boilers, not gas boilers, so it is not 0% finance for a gas combi and not ECO4.

What to do if you can’t afford a new boiler

Check whether you qualify for ECO4 or a council ECO4 Flex route first, then get quotes and compare any finance on total cost. There is no cash grant for a new gas boiler: ECO4 is paid by energy suppliers, and the Boiler Upgrade Scheme does not fund gas boilers.

1. Run the free ECO4 eligibility check. Ofgem lists boiler repair and replacement among the measures ECO4 can fund.
2. If you do not receive a listed benefit, ask whether your council runs an ECO4 Flex route (see our LA Flex scheme guide).
3. Expect conditions. Ofgem says energy suppliers decide the level of funding and may ask you to contribute, and you can apply through any obligated supplier, not only your own. Ofgem ECO FAQs
4. If you do not qualify, get more than one written quote and use the finance checklist above before you sign anything.

ECO4 is scheduled to run to 31 December 2026, so check sooner rather than later.

Red flags: free, 0%, and guaranteed language in ads

• Pressure to sign finance the same day while headlines shout “free boiler.”
• “Guaranteed free boiler” with a credit agreement buried in the terms.
• Upfront “application fees” to release funding.
• Cold calls insisting you must switch energy supplier for a grant.

Deeper trust checklist: Is the free boiler grant a scam?. For any gas boiler install work, verify the installer’s TrustMark and Gas Safe Register credentials before work starts.

How to check ECO4 eligibility with Apply Free Boiler

1. Share basic household and property details on our checker.
2. Complete the free eligibility check — no credit application.
3. We review and explain whether an ECO4-related route may be worth pursuing.
4. Survey, funding confirmation, and installation remain conditional on scheme rules and installer availability.

Apply Free Boiler does not provide interest-free boiler finance and is not FCA-regulated credit broking. You can also approach your council or obligated suppliers via GOV.UK directly.

Interest-free boiler vs ECO4 FAQs