In January 2024, a number of boiler manufacturers, including Baxi, Glow-worm, Ideal, Vaillant and Worcester Bosch, increased the wholesale price of each boiler they sold by between £95 and £120, or £114 to £144 with VAT1. The increases were a response to a proposed government scheme called the Clean Heat Market Mechanism1.
Under the planned scheme, boiler companies would have faced fines if heat pumps did not make up at least 4% of their sales, paying £3,000 per missed heat pump installation1. Companies campaigned against the proposal, and some raised gas boiler prices to absorb the potential cost of penalties, a move dubbed by some as a "boiler tax"1. In March 2024 the government announced it would delay the scheme, with a new proposed implementation date of April 20251.
Because manufacturers do not typically sell directly to households, whether a home gets money back depends on whether the installer passed the extra cost on1. Worcester Bosch told Which? it had added £120 to the cost of each boiler sold to a merchant customer between 1 January and 15 March 2024, and had since returned this in full to each customer1. Baxi, Ideal and Vaillant did not respond to a request for comment1. Wolseley, a distributor selling to traders, said it had refunded 99% of its customers by 11 April, and that remaining customers who paid in cash should get in touch with proof of purchase before 30 June for a full refund1. BOXT, which sells directly to consumers, said it had frozen its prices in January 2024, so its customers had not had the extra cost passed on1.
Which? notes that because the decision to return the money was made voluntarily by those companies, and was not due to a product fault, it is not technically a "refund" and does not carry the same protections for customers1. It adds that if a trader told a customer they were paying extra to cover this additional cost, the customer is within their rights to ask for it back1.
| Company | Position reported |
|---|---|
| Worcester Bosch | Added £120 per boiler sold to merchant customers, 1 January to 15 March 2024; returned in full1 |
| Baxi, Ideal, Vaillant | Did not respond to request for comment1 |
| Wolseley (distributor) | Refunded 99% of customers by 11 April; cash payers to claim by 30 June1 |
| BOXT | Froze prices in January 2024; no extra cost passed on1 |
Why it matters for households
The price rise reached the wholesale level, so its effect on any individual home depended on decisions taken further down the supply chain. A household that bought a boiler between 1 January and the end of March 2024 may have paid the extra, or may not, depending on whether the installer absorbed it or passed it on1. That makes the cost of a new boiler less predictable than a single national price change would suggest, and it means the paperwork from the purchase, rather than the brand on the boiler, is what establishes whether money is owed.
The episode also shows how a policy aimed at shifting sales towards heat pumps can move gas boiler prices before it takes effect. The mechanism was designed to make manufacturers answerable for the share of heat pumps in their sales, and the pre-emptive price rises were an attempt to cover that exposure1. For a household weighing a gas boiler against alternatives such as a tepeo Zero Emission Boiler, the timing of a purchase relative to scheme announcements has had a direct bearing on what was charged.
What happens next
The scheme's proposed implementation date is April 20251. Wolseley set a 30 June deadline for cash-paying trade customers to claim a full refund with proof of purchase1. Which? said it was recommending to its Trusted Traders that they proactively tell customers from the period whether their boiler cost was affected and, if so, when money can be expected back1.
Sources1 cited
- 'Boiler tax' repayments explained - Which?, which.co.uk