Air Source Heat Pumps

Yes. Modern heat pumps operate down to -25°C outside, and most still deliver full rated output at -10°C. Typical UK winters sit between 0°C and 5°C, so the unit spends most of the year well inside its comfortable range.

Efficiency does dip on the coldest days, that's normal physics, but a properly sized system is designed around peak demand at the coldest temperature your area sees. So when a real cold snap hits, the heat pump still keeps up.

The Boiler Upgrade Scheme pays up to £7,500 toward an eligible air source heat pump in England and Wales when you replace fossil fuel or electric heating and meet the published rules. The grant comes off your total cost upfront, before any finance is applied, not as a rebate later. Eligibility depends on your property, your EPC, and your existing heating system, all of which we check during the survey before submitting the application for you.

Quieter than most people expect. Manufacturer-published sound pressure for the air-to-water models we install is typically about 25–38 dB(A) at 3 metres on everyday low load (for example Samsung Gen 7 R290 Quiet Mode in the high 20s at 3 m, and Vaillant aroTHERM plus 5 kW 36 dB(A) at 3 m on its datasheet table). Larger capacities and peak winter output sit higher; the interactive ruler on our heat pumps page uses the same published envelope.

Your install still needs an MCS noise assessment for permitted development. We run that from manufacturer data for your property before we book the work in. For how the neighbour test works, see our MCS 020 guide.

Usually no. Heat pumps run cooler than a boiler, around 35°C to 45°C at the radiators instead of 60°C+. That means each radiator has to be big enough to heat its room at the lower temperature. Some already are. Some need swapping for a bigger panel.

In practice, most homes keep most of their radiators. A heat loss survey goes room by room and tells you exactly which ones need to change before anything gets ordered.

Around two weeks from quote to install. The fitting itself takes 2 to 4 days on site. A straight swap where your radiators are already compatible sits at the shorter end. If you need a new hot water cylinder, larger radiators, or extra pipework, it stretches to the full four days. Your heating is off briefly during the changeover, and you'll have hot water back before the end of the day.

Domestic air source heat pumps run from 3.5 kW to 16 kW. The right size depends on how much heat your home actually loses, which comes down to floor area, insulation, glazing, and the coldest typical temperature in your area. As a rough guide, a well-insulated 3-bed semi usually lands between 6 and 10 kW.

Sizing matters. Oversize the unit and it cycles on and off, costs more, and runs inefficiently. Undersize it and it can't keep up on the coldest days. A proper heat loss survey pins the number down before anything gets ordered.

Usually not. Most domestic heat pump installs count as permitted development in England, Scotland and Wales, so no planning application is needed. There are conditions on the unit's size, position, and noise that vary slightly by nation, and listed buildings or conservation areas always need separate consent.

From 28 May 2026, MCS 020 is the only certification route for permitted development in England. We'll assess your specific property during the design stage and let you know what applies.

A gas boiler can't give you more heat than the energy in the gas it burns. About 10% gets lost up the flue, so the best it does is turn 90% of what you put in into heat.

A heat pump works the other way around. It doesn't make heat, it moves heat that's already in the outside air into your home. For every 1 unit of electricity it uses, you get back 3 to 5 units of heat. The cooler the water it sends to your radiators, the more efficient it gets, so a system running at 35°C does better than one running at 55°C. SCOP figures for any specific model can be cross-checked in the MCS Product Directory.

Properly sized installs in well-insulated homes deliver noticeable savings on running costs, and pairing the heat pump with solar panels or a smart electricity tariff stretches those savings further.

Yes, the two stack. The Boiler Upgrade Scheme grant of up to £7,500 comes off the headline install price first. Your finance agreement then covers what's left after the grant, not the full sticker price.

That means smaller monthly payments than you'd see without the grant. We confirm grant eligibility during the survey and apply it before any finance figures get quoted on your heat pump proposal.

Getting an initial quote uses a soft search, which doesn't leave a mark on your credit file and isn't visible to other lenders. You can see what you'd likely be offered without any impact on your score.

When you choose to proceed with a finance agreement, the lender runs a hard search as part of the formal application. That does show on your file. See our finance page for how the soft and hard search stages work in practice.