The Sussex guide to air source heat pumps

The Boiler Upgrade Scheme gives £7,500 towards an air source or ground source heat pump in England and Wales, or £9,000 until March 2027 if your home is heated by oil or LPG and has no mains gas. There's also £2,500 for air-to-air heat pumps and £5,000 for biomass boilers, and funding is confirmed through to 2029/30.

You don't fill in any forms. As an MCS-certified installer, we check you qualify, apply to Ofgem on your behalf and take the grant off your quote. Ofgem then contacts you to confirm before the work starts.

Yes, for smaller buildings. The Boiler Upgrade Scheme covers small and medium non-domestic buildings in England and Wales as well as homes, for systems up to 45kW. For larger projects, see Ofgem's business energy efficiency grants and schemes page, or talk to us about what's available.

The main difference is where they draw their heat from. An air source heat pump takes heat from the air outside, even when it's cold, and uses it to warm your home and hot water. They're easier and cheaper to install, which makes them the popular choice, though they work a little harder on the coldest winter days.

A ground source heat pump draws heat from pipes buried in the ground. It's more efficient in cold weather, but needs more outdoor space and costs more to install because of the digging. Both are low-carbon alternatives to a gas or oil boiler.

A boiler burns gas or oil to make heat. A heat pump moves heat from the outside air into your home, so it typically produces three to four units of heat for every unit of electricity it uses, and more from a well-designed system.

That efficiency means lower carbon emissions and, with good design and a heat pump tariff, lower running costs. A heat pump costs more to install than a boiler, but the Boiler Upgrade Scheme grant helps with that.

An air-to-water heat pump moves heat from the outside air into water, which heats your home through radiators or underfloor heating and gives you hot water for your taps. It's the right choice if you have a wet central heating system.

An air-to-air heat pump blows warm air into your rooms through indoor units instead. It doesn't heat your water, but it's simpler to install and can cool your home in summer. The Boiler Upgrade Scheme gives £2,500 towards air-to-air and £7,500 towards air-to-water.

Typically around a week, depending on your home and how much of the heating system needs changing. That covers fitting the outdoor unit and hot water cylinder, any radiator upgrades, and setting up and testing the system. See our buying process for each step.

Typically 15 to 20 years, and often longer with an annual service and prompt repairs when something needs attention.

It depends on how much heat your home loses, which comes down to its size, insulation and windows. We work it out with a room-by-room heat loss calculation, so your heat pump is sized for your home rather than guessed.

Usually, yes. Heat pumps work with radiators and underfloor heating, and many existing radiators can stay. Some may need upgrading so the system runs efficiently at lower temperatures, and we'll tell you which during the survey.

Not beyond the usual ones. You'll need outdoor space for the unit, with clearance around it for airflow, and room inside for a hot water cylinder. Most installations fall under permitted development, though listed buildings and homes in conservation areas may need permission first. See our planning permission guide.

Yes. In a new build, the heat pump can be designed in from the start for the best efficiency. In an existing home, it can usually be fitted with a few changes to radiators or pipework. The Boiler Upgrade Scheme grant doesn't cover new builds, except custom self-builds.