Boiler Energy Savings Calculator
Estimate how much you could save on gas bills by replacing an older boiler with a modern, efficient boiler. Adjust the figures to calculate your potential annual savings.
Your Home and Boiler
This calculator estimates the gas-cost difference for the same useful heat demand. Results are illustrative, not guaranteed.
Your Estimated Savings
How Much Can a New Boiler Save?
A modern condensing boiler may use less gas than an older, inefficient boiler to deliver the same useful heat. The potential saving depends on the efficiency difference and your annual gas use.
Boiler Efficiency
A higher-efficiency boiler can reduce the amount of fuel needed to heat your home. Boiler age alone does not establish its exact efficiency.
Heating Controls
Timers, room thermostats and correctly configured heating controls can help avoid unnecessary heating.
Home Insulation
Suitable insulation and draught-proofing can reduce heat loss and lower heating demand, with or without a new boiler.
What Affects Boiler Energy Savings?
Property Size
Larger homes generally require more heat. Boiler sizing should also account for heat loss and hot-water demand.
Heating Habits
Thermostat settings, heating hours, occupancy and hot-water use all influence gas consumption.
Gas Prices
The same reduction in gas use has a different financial value depending on your tariff's unit rate.
Boiler Energy Savings FAQs
How accurate is this calculator?
It is an illustrative estimate based on the figures entered. Actual savings vary with real boiler performance, property heat demand, heating habits and energy tariffs.
How much could I save by replacing an old boiler?
Your potential saving depends on the current boiler's efficiency, the replacement boiler's performance and your annual gas use. The result is not a guarantee of future savings.
Does this calculator include standing charges?
No. It estimates gas usage costs only. Gas standing charges, electricity, maintenance and finance costs are excluded.
How is the boiler payback period calculated?
The simple payback estimate divides the installation cost by the estimated annual saving. It does not account for future energy prices, maintenance or other costs.
Should I replace my boiler based only on this result?
No. Use the estimate as a starting point and obtain a written quote and assessment from a qualified heating engineer before deciding to replace your boiler.
Disclaimer: This tool provides general information only. It is not an energy audit, professional heating assessment or guarantee of savings. Figures are based on simplified assumptions.