Boiler Upgrade Scheme: who qualifies and how to apply

What the grant pays

The Boiler Upgrade Scheme is a government grant towards replacing fossil fuel heating with a low carbon system. It is open in England and Wales; Scotland and Northern Ireland run separate schemes. The grant is not paid to you. It is deducted from the installer's bill.

Until March 2027, a home heated by oil or LPG with no mains gas connection can get an extra £1,500 on top for an air or ground source heat pump. One grant is allowed per property.

Who qualifies

Two conditions apply to everyone:

• You own the property. That includes a second home, a property you let to tenants, or a business.
• You are replacing a fossil fuel heating system: gas, oil, LPG or electric.

Some properties are excluded:

• Most new builds still being built by a developer. A finished home that already has a fossil fuel boiler can qualify, and so can a self-build in some cases.
• Social housing.
• A property that has already had government funding for a heat pump or biomass boiler.

The system has to be a full replacement. A hybrid, where a heat pump works alongside a gas boiler that stays, does not qualify. There is a capacity limit of 45kWth for a single system, which only matters for very large properties. Biomass boilers carry extra conditions: the property must be rural and off the gas grid, and the boiler must have an emissions certificate.

How applying works

• Get quotes from MCS certified installers. Only work by a certified installer qualifies, and the MCS website lets you check a company's certification.
• Confirm with the installer that the property is eligible.
• Agree a quote. It should show the full price and the grant deducted from it.
• The installer applies to Ofgem, which runs the scheme, on your behalf.
• Ofgem contacts you to confirm the installer is acting for you. Reply promptly, because the application waits on your reply.
• The heat pump must be installed and commissioned within 120 days of the application.

After installation, Ofgem or MCS may contact you to check the work was done.

What you still pay

An air source heat pump typically costs £7,000 to £13,000 installed before the grant, so many households pay somewhere between nothing and £5,500 after it. The parts of the job that push a quote up are the ones the grant does not change:

A heat pump runs most efficiently at a low water temperature, so several radiators usually need to be larger than the ones a gas boiler needed. That is decided by a room by room heat loss calculation, and a reliable quote is based on one.

How long the process takes

Expect a few weeks between the first survey and the installation. The installer needs time for the heat loss survey, to design the system and to order the unit, the cylinder and any larger radiators. The application to Ofgem is usually made once you have agreed the quote, and the 120 day clock starts then, so installers usually apply when the equipment is in hand rather than on the day of the first visit. The installation itself typically takes a few days. When it is finished you should receive the MCS certificate and the commissioning paperwork; keep both with the property's records.

Checks before you sign

Check the installer's MCS certification yourself rather than relying on a logo. Ask for the heat loss calculation and the design flow temperature in writing. Ask where the outdoor unit will go and how loud it is, because siting and noise are conditions of permitted development, and listed buildings and conservation areas have stricter rules. And ask what deposit is taken, and when, relative to Ofgem's approval of the grant.

Keeping an application on track

Applications go through smoothly when the installer is MCS certified for the technology being fitted, the property has not received heat pump funding under an earlier scheme, the system is a full replacement rather than a hybrid, and the cylinder and radiators are ordered in time to finish within the 120 day window. A clear timetable in the quote takes care of the last one.