Gas vs Heat Pump Calculator: Heating Cost Over 15 Years

Heating upgrades are expensive, long-lived decisions. A new gas boiler is cheaper upfront; a heat pump usually costs more to install but can slash annual energy bills if your home is suitable and electricity/gas prices cooperate.

A gas vs heat pump calculator spreads install cost, maintenance, and energy use over your analysis period so you see break-even clearly — including energy price inflation.

What COP Means for Your Bill

Coefficient of Performance (COP) is heat output divided by electricity input. A COP of 3.5 means roughly 1 kWh of electricity delivers 3.5 kWh of heat. That is why heat pumps can beat gas even when electricity costs more per kWh than gas.

Real-world seasonal COP depends on outdoor temperatures, radiator sizing, and insulation. Overselling COP is a common sales mistake — use conservative values in the calculator unless you have a professional heat-loss survey.

Upfront Cost vs Lifetime Cost

Expect heat pump installs to cost significantly more than a like-for-like boiler swap, especially if you need larger radiators or electrical upgrades. Grants and incentives can change the math overnight — always update the install input with net cost after subsidies.

Maintenance for heat pumps is often comparable or slightly lower than gas, but repairs on outdoor units can be pricey. Include a maintenance line so the model stays honest.

15-Year Cost Illustration

The chart below is a simplified household example. Your climate, tariffs, and install quotes will move the crossover point. Re-run whenever energy prices or subsidy rules change.

When Gas Still Makes Sense

Short ownership horizons, heritage buildings hard to retrofit, or very cheap gas with expensive electricity can keep boilers competitive. If you plan to sell in three years and buyers in your area do not pay a premium for heat pumps, you may not recover the install premium.

• Get a heat-loss survey before trusting COP claims
• Use net install cost after grants
• Model gas and electricity inflation separately
• Check electrical capacity and radiator suitability

Putting It Into Practice

Run TrendMandi’s Gas vs Heat Pump Calculator with contractor quotes, then check Solar Payback if you will pair panels with a heat pump — self-consumed solar electricity can improve heat-pump economics further.