What is changing
From April 2025 the Clean Heat Market Mechanism (CHMM) will require large boiler makers to hit targets for heat-pump installations or pay £3,000 per shortfall. Aquashield, a heating firm, stated: "UK manufacturers of domestic gas boilers we will have no choice but to pass on (or add) the cost of these punitive fines (or boiler lax) as a CHMM Levy onto the cost of boilers". The company expects the levy to add as much as £300 before VAT, taking the real hit closer to £360.
Who it affects
The rules apply to firms supplying 20,000 or more gas boilers or 1,000-plus oil boilers a year. Baxi has already added a £120 surcharge to its residential models. Typical installed combi prices currently sit between £2,000 and £4,000, so the extra charge will land on top of those figures for anyone replacing a boiler after the deadline.
What households should do
If you need a new boiler soon, getting quotes and booking work before April 2025 avoids the levy. We have plenty of energy comparison tools that can help you check current tariffs and any grants that might offset higher upfront costs. Delaying a straightforward like-for-like swap could simply mean paying the extra £300–£360 later.
