Heat pump vs boiler
Replacing a boiler with a heat pump can cut energy use and add cooling — but the two heat your home very differently. Here is the comparison.
Key differences
A boiler burns gas, oil or propane to heat water for radiators or radiant floors. A heat pump uses electricity to move heat, and (for air-source) usually delivers it as warm air, though air-to-water heat pumps can feed existing radiators.
| Heat pump | Boiler | |
|---|---|---|
| Energy | Electricity (moves heat) | Burns fuel |
| Efficiency | 250–400% (COP) | 80–95% (AFUE) |
| Cooling | Yes | No |
| Emissions | None on-site | Combustion |
| Works with radiators? | Air-to-water models, yes | Yes |
Running cost
Because a heat pump is 2–4× efficient, it usually beats an oil or propane boiler on running cost by a wide margin, and adds summer cooling. Versus a cheap gas boiler, the comparison depends on your local electricity-to-gas price ratio — use our savings calculator to check. An air-to-water heat pump can often reuse your existing radiators, lowering install cost.
Which should you choose?
If you heat with oil or propane, a heat pump is usually a clear upgrade. If you have a newer, cheap gas boiler, weigh the cooling and emissions benefits against your local prices. In cold climates, a cold-climate or hybrid setup keeps you covered on the coldest days.
Frequently asked questions
Is a heat pump cheaper to run than a boiler?
Versus oil and propane boilers, almost always. Versus a cheap gas boiler it depends on your local electricity-to-gas price ratio.
Can a heat pump replace a boiler with radiators?
Yes — an air-to-water (or ground-source) heat pump can feed existing radiators or radiant floors, though larger radiators help at lower water temperatures.
Do I lose hot water if I replace my boiler?
No — pair the heat pump with a hot-water cylinder or add a heat pump water heater to handle domestic hot water.
Related
Sources & further reading
Educational guide, reviewed against US DOE & ENERGY STAR guidance and updated June 2026. Estimates only — not a substitute for a professional assessment or Manual J load calculation.