Electric Combi Boilers CompanyNO-NONSENSE ELECTRIC HEATINGWorking prototype
PLAN YOUR SWITCH

What could an electric
boiler cost to run?

Tell us about your home. Explore the cost. Make a more informed boiler decision.

Electric boilers are generally more expensive to run than gas. Your home’s heat demand and electricity tariff make the difference.
01

Start with your home

Early planning estimate. These property assumptions are provisional and have not been calibrated against ECBC customer homes. Use your energy bill where available.

Start with your EPC’s floor area if useful, excluding unheated areas. Flats vary by floor and exposure; substantial glazing, very high ceilings and unusual construction need an individual assessment. This route is not suitable for Passivhaus or other exceptionally low-energy homes.

See the property assumptions

Formula: heated floor area × annual heat-demand band × property × climate × usage factors. These are transparent prototype scenarios, not SAP calculations, EPC grades or validated prediction intervals. Building age is not added as a separate multiplier because it can duplicate the insulation assumption.

Override both values together using an assessed range for your property. The other selected factors still apply. If you already have an annual heat-demand figure, use the direct-entry route instead.

02

Add your hot-water use

Count showers and baths across the whole household.

Water temperatures, baths and taps

Temperatures are calculation assumptions, not storage or safety settings. Incoming water temperature changes through the year.

03

Your electricity tariff

28p is an illustrative rate, not a current tariff quote. Enter your own rate. Add cylinder, pipework and standby losses if known; zero excludes them. Do not count losses already included in your demand figure.

Off-peak electricity
04

Solar panels & battery storage Optional

Explore electricity bought from the grid and the value of using your solar energy. Leave both options off to keep your original estimate.

Understand the estimate

Demand drives cost

A boiler’s kW rating describes power, not annual consumption. Radiator count and hours on a timer cannot tell us exactly how much heat your home needs.

Every assumption is visible

Water energy = litres × temperature rise × 0.001163 kWh. We annualise weekly water use using 365 ÷ 7. Cost = electricity use × unit rate.

Check the whole system

This prototype assumes 1 kWh of electricity per 1 kWh of heat, before separately added losses. Actual system performance and usage need checking before a purchase.

Sources and scope

Reviewed 15 October 2026. General running-cost context: Energy Saving Trust: electric heating. The water calculation uses the standard heat capacity approximation for water. Property bands (40–80, 80–140, 140–220 and 40–220 kWh/m²/year) and all property, climate and usage factors are provisional development assumptions, not published benchmarks. They require calibration before public release. Context: Passivhaus Trust: periodic heating explains why fabric and heating patterns matter, and uses treated floor area. Its stock-level figures do not validate these bands or individual predictions, and are not used directly in this calculator. Example usage, tariffs, gas efficiency and the 20% sensitivity in the bill/direct routes are assumptions. No model-specific performance or savings are claimed.