Heat pumps
Heat pumps
The technology, when it suits, when it doesn't, including the cold-weather question and what makes a UK install actually perform.
Reading order: beginner first
What is a heat pump?
A heat pump is a fridge running backwards. Instead of moving heat out of a small box, it moves heat into your home from the air or ground outside. It uses electricity to do the work, but for every 1 kWh of electricity it uses, it delivers 3–4 kWh of heat. That is why it can heat your home for less than a gas boiler does, even with electricity costing more per kWh than gas.
Do heat pumps work in cold weather?
Yes. Modern UK air-source heat pumps are tested to operate at -20°C and remain efficient down to about -10°C in real-world use. That is well below typical UK winter lows. Norway, where winter temperatures regularly drop below -20°C, has heat pumps in 6 of every 10 homes. The 'heat pumps don't work in winter' claim is one of the most persistent UK retrofit myths, and it's wrong.
Will a heat pump work in my old British home?
Often, yes. But the order matters. Solid-wall pre-1919 homes typically need fabric work first; 1930s cavity homes usually want cavity fill and a loft top-up before sizing the heat pump; better-fabric post-1960 stock can often go ahead with the heat pump first. 'Old' alone doesn't disqualify; uninsulated does.
Heat pump running costs vs gas: the honest numbers
On the right tariff and with a properly installed system, a heat pump typically saves £100–£200/year vs the same home on gas. On a standard tariff with a poor install, you can pay more. Tariff choice, install quality, and home fabric together account for the variance, not the technology itself.
The Boiler Upgrade Scheme explained
The Boiler Upgrade Scheme is a £7,500 government grant toward an air-source heat pump install in England and Wales. Your installer applies on your behalf and the grant comes off your invoice, not refunded later. As of late 2025, around 86% of applications are approved.