Waitz Energy
Free Tool

Heat Pump Savings Calculator

See what switching from a gas boiler to an air source heat pump would actually cost and save you. Real UK energy prices, no sales pitch.

Your Property

Your current monthly spend on heating fuel
Cavity walls filled, loft insulated = Average

Prices: Ofgem Q2 2026 cap. Gas 6.76p/kWh, electricity 24.50p/kWh, oil 5.89p/kWh, LPG 7.64p/kWh. ASHP COP 3.2 average (seasonal).

Annual Heating Cost

£1,440
Current
system
£660
Heat
pump
Save £780/year 54% lower bills
10
years payback
with BUS grant
£7.8k
lifetime saving
over 20 years

Installation Cost Breakdown

Typical ASHP installation £12,000
BUS grant (available) -£7,500
You pay £4,500

Carbon Reduction

1.8
tonnes CO2/year saved
🌳🌳🌳🌳🌳🌳🌳🌳🌳
Equivalent to 9 trees planted/year

The honest bit

  • - These are estimates based on typical UK figures. Your actual savings depend on your home's specific heat loss, which varies hugely.
  • - Heat pumps work best in well-insulated homes. If your insulation is poor, fix that first - you'll save more per pound spent.
  • - COP of 3.2 is a realistic seasonal average for UK air source heat pumps. Manufacturers claiming 4+ are quoting lab conditions.
  • - The BUS grant (£7,500 for ASHP) is available until March 2028. Check GOV.UK for current eligibility.
  • - We'd always recommend a proper heat loss survey before committing. A calculator can't replace that.

Want the real numbers for your home?

A proper heat loss survey tells you exactly what a heat pump would cost and save for your specific property. We cover Bedfordshire, Cambridgeshire, and Hertfordshire.

Book a Free Assessment

Related reading

Heat Pumps: What the Tabloids Won't Tell You Who Pays for Energy Upgrades in UK Properties Do I Need an EPC? Complete Guide for UK Landlords