Would a heat pump actually be cheaper to run than your gas boiler?
There is one number that settles it: the efficiency a heat pump would have to hit, in your house, to cost the same as the gas you burn now. Compare that against what heat pumps actually achieve and you have your answer.
This works from the gas figure on your own bill, so there is no modelling of your house at all. Your meter already knows how much gas you burned. The only estimate left is how much of it your boiler turned into heat.
2 The number that decides it
efficiency a heat pump needs
in your house, to break even
median measured across
428 real UK installations
What each would cost you a year
3 The working
Both sides include standing charges. Going all-electric removes the gas standing charge, which is worth about £108 a year on its own and which most comparisons leave out.
4 What this cannot tell you
- It assumes a heat pump would deliver the same amount of heat your boiler does now. In practice people often end up warmer, because heat pumps run steadily rather than in bursts, and that uses more energy.
- Efficiency depends heavily on design. A system run at a low flow temperature into big radiators does far better than one pushed to 55°C.
- Prices move every three months with the Ofgem cap, and a dedicated heat pump tariff can change the answer completely. Try one in the electricity box above.
- It says nothing about the cost of installing it. That is on the size and cost calculator.
5 Method and sources
How the break-even efficiency is worked out
- Your gas use is multiplied by your boiler's efficiency, to get the heat actually delivered into the house.
- Your gas bill is that gas use at the gas unit rate, plus both standing charges, because you currently pay for a gas connection and an electricity connection.
- A heat pump pays only the electricity standing charge. Subtract it from your current bill to get what is left for electricity units.
- Divide the heat needed by that budget. The answer is the efficiency the heat pump has to reach to come out level.
Why we do not use the efficiency on the box
Every number this page uses
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