Heat pump vs gas boiler: which is cheaper to run?

A condensing gas boiler turns about 95% of the gas energy into heat. A heat pump instead moves heat from the outside air: over a season it delivers 3–4 kWh of heat for every kWh of electricity. That seasonal efficiency is called SCOP.

Which one is cheaper to run therefore depends on what you pay for a kWh of electricity compared with a kWh of gas.

The price-ratio rule

Divide your electricity price per kWh by your gas price per kWh. A heat pump is cheaper to run when its SCOP is higher than that ratio multiplied by 0.95 (the boiler’s efficiency).

• Italy (€0.27/kWh electricity, €0.12/kWh gas): ratio 2.25 → a SCOP above 2.1 is enough.
• France (€0.25 vs €0.11): ratio 2.3 → SCOP above 2.2.
• Netherlands (€0.30 vs about €0.14): ratio 2.1 → SCOP above 2.0.
• Germany (€0.39 vs €0.12): ratio 3.25 → SCOP above 3.1.
• USA ($0.18/kWh vs $1.45/therm, about $0.05/kWh): ratio 3.6 → SCOP above 3.5.
• UK (£0.26 vs £0.064 at the price cap): ratio 4.1 → SCOP above 3.9.

What it means for you

Where electricity is cheap compared with gas (Italy, France, the Netherlands), almost any modern heat pump beats a gas boiler on running costs. Where electricity is expensive (UK, Germany, much of the USA), you need an efficient, well-designed system — or a heat-pump electricity tariff — to save money. The ratio also changes when prices change, so check it with your own bills.

Heat pumps work best with low-temperature emitters (underfloor heating or larger radiators) and a well-insulated home, which is also what pushes the SCOP up.

Run the numbers for your home

The calculator works for any city in the world: it uses your local climate and your energy prices to compare a heat pump with your current heating, including installation cost and payback time.