Running-cost simulator
See what you’d really pay to run a heat pump.
Compare your current boiler against a heat pump — on your tariff and on the smartest tariff for your home — then layer in solar and a battery to see the full payback and 20-year return on a complete low-carbon home upgrade.
Your home today
Heat delivered to your home each year (space heating + hot water).
Lights, appliances, cooking — everything except heating.
Your current tariff
Pick the tariff you’re on today — or upload a bill below for exact rates.
The default single-rate tariff most homes are on. No cheap window.
Upload your bill for an exact result
Snap a photo or attach a PDF. We’ll read your MPAN, unit rates and annual usage automatically.
What we’d install
Our designs typically achieve 4.0+ with weather compensation.
From 10 kWh in 5 kWh steps up to Sigenergy's 48 kWh maximum.
Mains gas now
£2,103
On Standard Variable · per year
Heat pump
£1,861
On Standard Variable · per year
Heat pump
£1,755
On Octopus Flux · per year
Recommended tariff: Octopus Flux
Premium evening export — best paired with solar and a battery.
Full saving vs your mains gas today
£348/yr
incl. £106/yr from the smarter tariff
Annual running cost
Each upgrade stacked on the recommended Octopus Flux tariff.
The full upgrade — heat pump, solar & battery
Total investment
£20,130
after £7,500 grant
You save every year
£1,754
vs your boiler today
Payback
11.5 yrs
then it’s pure saving
Solar generation
5,700 kWh/yr
Grid import
2,425 kWh/yr
CO₂ avoided
3.1 t/yr
How we cost the upgrade
Heat pump ~£16k is a typical average installed cost before grant — your fixed price follows an MCS heat-loss survey. Solar & battery are priced from our current equipment costs and include full installation, commissioning, workmanship guarantees and MCS certification. Domestic heat pumps carry 0% VAT.
20-year outlook
Utility savings, 20 yrs
£80,266
with ~8%/yr energy inflation
Return on investment
299%
≈ 14.9% a year
Breaks even
year 9
then pure profit
A net return of £60,136 over 20 years after recovering your £20,130 investment — plus a warmer, lower-carbon home and protection from future energy-price rises.
All figures shown are indicative average costs for guidance only, not a guarantee. Every home is different, so your fixed-price proposal follows a full MCS heat-loss survey. Investment uses typical UK average installed costs; the Boiler Upgrade Scheme grant is applied to the heat pump. The 20-year outlook assumes ~8% annual energy-price inflation, in line with the last two decades of UK price rises.
Get my fixed-price proposal