# The Clean Heat Market Mechanism (Amendment) Regulations 2025, Note: Explanatory note


(This note is not part of the Regulations)
These Regulations, which apply in England and Wales, Scotland and Northern Ireland, amend the Clean Heat Market Mechanism Regulations 2025 (S.I. 2025/81), which established the low-carbon heat scheme known as the Clean Heat Market Mechanism (“CHMM”).
The CHMM is designed to provide the UK’s heating industry with the confidence and incentive to invest in developing the low-carbon heat pump market. It places an obligation on manufacturers supplying gas and oil boilers in the UK market. Manufacturers must meet targets for the installation of heat pumps in existing properties in proportion to their sales of fossil fuel boilers. Manufacturers can do this by supplying heat pumps themselves or by acquiring credits from other manufacturers.
The Microgeneration Certification Scheme (MCS) is to be named as the sole certification for the CHMM. Accordingly, Regulation 5 changes the definition of “certification scheme” to have the meaning in amended regulation 6. Regulation 7 appoints MCS as the certification scheme and gives the Secretary of State a power to approve a subsequent version of the MCS.
Regulation 6 amends the definition of a “hybrid heating system” so that a hybrid heating system (which incorporates both a heat pump and a fossil fuel appliance) is not required to provide hot water if no hot water is needed for the building. It does not amend the kind of heating appliance (hybrid heat pump) that the CHMM applies to.
Regulation 8 updates the low-carbon heat target for scheme years beginning 1st April 2026 until the target is amended again for future scheme years. The new target will be 8% of relevant boiler sales.

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Source: https://www.legislation.gov.uk/uksi/2025/1208/note (the official version)
Page: https://openlegislation.uk/clean-heat-market-mechanism-amendment-regulations-2025/note
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.