The government has decided to remove the option for multiple certification schemes to certify clean heat installations funded through the Boiler Upgrade Scheme, Energy Company Obligation 4, Warm Homes: Social Housing Fund and Warm Homes: Local Grant. The decision, set out in the government response to Part 2 of the Boiler Upgrade Scheme and certification requirements consultation, was published on 31 October 20251. The consultation ran from 11am on 30 April 2025 to 11:59pm on 11 June 2025 and received 262 responses to Part 2 from installers, manufacturers, representative and trade associations, non-governmental organisations, local government and other stakeholders1.
The change means the Microgeneration Certification Scheme (MCS) becomes the only route to certify installations under those four schemes, with the option for equivalence removed from scheme regulations and guidance1. The government states this does not affect clean heat measures not currently required to be certified by MCS, such as heat networks, which will be covered by the forthcoming Heat Network Technical Assurance Scheme, or any measures covered by PAS 20301. The response applies to England, Scotland and Wales1.
"Having considered the responses, the government has decided to proceed with removing the option for multiple certification schemes to certify installations under the Boiler Upgrade Scheme, Energy Company Obligation 4, Warm Homes: Social Housing Fund and Warm Homes: Local Grant."
The government describes the move as an interim step ahead of longer-term reforms to the consumer protection landscape, with detail of those proposed system reforms to be set out as part of the Warm Homes Plan1. The Part 2 response does not set out a date for when the certification change takes effect.
A separate government response covering Part 1 of the consultation, on amendments to the Boiler Upgrade Scheme itself, was published on 18 November 20251. That response sets out intentions to begin providing grants of £2,500 for air-to-air heat pumps in domestic properties and £2,500 for heat batteries once appropriate product, design and installation standards, including robust consumer protections, are in place; to amend eligibility criteria to allow more heat pump installations combined with other electric heating appliances; to allow exhaust air heat pumps; to relax the requirement to provide a valid Energy Performance Certificate from 2026 to 2027 onwards; to assess the MCS Customer Commitment as a consumer code before deciding whether to approve it for the scheme; and to require installers to deduct the grant amount from the upfront cost of eligible plant1. Further work on third-party ownership of BUS-funded heating systems will be undertaken before eligibility is determined1. The Part 1 response received 357 responses1.
| Consultation part | Responses received | Response published |
|---|---|---|
| Part 1: Amendments to the Boiler Upgrade Scheme | 357 | 18 November 2025 |
| Part 2: Certification requirements for clean heat schemes | 262 | 31 October 2025 |
Why it matters for households
Certification determines which installers can carry out work that qualifies for public funding. Where a single scheme is mandated, households applying for a Boiler Upgrade Scheme grant, ECO4 or the Warm Homes schemes will need an installer certified under MCS rather than an equivalent alternative. The government's stated aim is to simplify certification requirements and enhance consumer protections, and it frames the change as an interim step before wider reforms1. For a home's energy independence, the practical effect is on the route to a funded installation rather than on the technology itself: the certification requirement sits alongside eligibility rules such as whether a home has a gas boiler and whether social housing can access grants. The Part 1 intentions, if implemented, would widen the technologies eligible for support and change how the grant reaches the household, with installers required to deduct the grant from upfront costs1.
What happens next
The government says it will proceed to introduce scheme regulations to Parliament to give effect to the Part 1 changes, as parliamentary time allows, and will announce the timing of those changes in the coming weeks, along with guidance for installers and consumers on how the changes affect the application process1. No equivalent timetable is given in the Part 2 response for the certification change, and the date on which MCS becomes the sole certification scheme has not been reported1.