Clean Heat Market Mechanism (CHMM) 2025: Updated

Understanding the clean heat market mechanism

What the scheme aims to do

The Clean Heat Market Mechanism (CHMM) is part of the UK government’s plan to reduce carbon emissions and modernise home heating.

It officially came into effect in April 2025, after consultation with industry and energy experts.

Its main goal is to support the shift from fossil fuel boilers to low carbon heating, mainly air source heat pumps.

Instead of targeting homeowners, the CHMM puts responsibility on boiler manufacturers, requiring them to sell a percentage of heat pumps alongside gas and oil boilers.

This approach encourages manufacturers to innovate, invest in cleaner heating technology, and help the UK reach net zero by 2050.

How the policy works

Each manufacturer has a heat pump sales target based on their total boiler sales.

For the first phase, running from April 2025 to March 2026, at least 6% of their heating appliances must be heat pumps.

If they fail to meet this goal, they face a £3,000 fine for every missed unit.

This table helps show the expected scale of progress.

The aim is to make heat pump production more financially rewarding than relying solely on fossil fuel boilers.

Why the government introduced it

The CHMM was introduced to address the slow rollout of low carbon heating in the UK.

Although the Boiler Upgrade Scheme offers grants for homeowners, heat pump adoption remained below expectations.

By focusing on manufacturers, the government hopes to:

• Increase investment in heat pump innovation and production.

• Lower costs for homeowners through competition and scale.

• Prepare the market for future limits on fossil fuel boiler sales.

What the clean heat market mechanism means for homeowners

There is no boiler tax for households

Some reports have called the CHMM a “boiler tax”, but that’s incorrect.

The policy only applies to manufacturers. There are no government charges or taxes for households.

Manufacturers who face fines may adjust pricing to recover costs, but any changes will likely be small and gradual.

There is no direct cost added to your boiler installation.

You can still buy and install a gas boiler

As of November 2025, gas boilers remain fully available.

The CHMM does not ban them or force homeowners to switch to heat pumps.

Instead, it aims to increase choice, giving households more affordable low carbon options over time.

It helps prepare for future heating policy

The CHMM supports the wider move towards cleaner energy. By encouraging heat pump availability, it helps prepare for:

• Larger grants for heat pump installations.

• More government funding for insulation and energy upgrades.

• A stronger UK network of trained heating engineers.

Targets and key dates to know

Launch and first year target

The scheme launched in April 2025, setting the first heat pump sales target at 6% of total annual heating appliance sales.

Review period and potential updates

The Department for Energy Security and Net Zero (DESNZ) will review progress in early 2026.

Depending on market performance, the next phase could raise the target to 10% or higher by 2027.

Future plans

Future policy updates may include extra funding for home insulation and low carbon heating systems to help reduce energy bills for homeowners.

How the clean heat market mechanism supports low carbon heating

Encouraging innovation and competition

Linking financial penalties to heat pump sales drives innovation.

Manufacturers are developing quieter, more compact models for smaller homes and improving system efficiency in colder climates.

Building a stronger installer network

The CHMM works alongside national training schemes to expand the number of qualified heat pump engineers.

This helps ensure installations can keep pace with growing demand.

Lowering long-term costs for households

As sales increase, production costs should fall.

Over time, homeowners will benefit from more affordable and reliable low carbon heating systems.

Common misconceptions about the clean heat market mechanism

It does not ban gas boilers

Gas boilers are still legal and available. The CHMM only requires manufacturers to increase their share of clean heating products.

It is not a tax on homeowners

There are no direct government charges for households.

Any pricing changes depend on manufacturer decisions, not policy.

It does not mean you must install a heat pump

There is no requirement to switch heating systems. The goal is to expand future options, not restrict current ones.

What homeowners can do to prepare for future heating changes

Stay informed about grants

Schemes like the Boiler Upgrade Scheme offer grants of up to £7,500 for eligible heat pump installations.

Keeping updated helps plan future upgrades affordably.

Get annual boiler servicing

Regular servicing keeps your boiler safe and efficient, helping lower emissions and energy costs while you plan ahead.

Consider future-proof systems

When replacing your boiler, ask about heat pump-ready or hybrid systems that make future upgrades easier.

The clean heat market mechanism in 2026 and beyond

As of November 2025, the CHMM has been active for six months. Early government reports suggest that most major manufacturers are close to meeting the 6% target.

A full review is expected in spring 2026, which could raise targets and expand funding support.

Homeowners will continue to have access to both gas and heat pump systems as the UK gradually transitions toward low carbon heating.

What the Clean Heat Market Mechanism means for you as a homeowner

The Clean Heat Market Mechanism focuses on manufacturers, not households.

It’s designed to make cleaner heating options more available, more affordable, and better supported across the UK.

For homeowners, it means greater choice, improved technology, and no sudden changes to how you heat your home.

Staying informed about available grants, servicing your boiler regularly, and planning future upgrades will help you prepare for upcoming energy changes confidently.

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