Heat pump vs gas boiler running costs
Compare the entered running costs using your own usage and current fuel prices.
After you calculate
See how your heating costs compare
Add your heating demand, fuel prices and equipment performance, then calculate to see your results.
Gas boiler cost
Shown after calculationHeat pump cost
Shown after calculationRunning costs
Energy needed
Full calculation
Both systems are compared using the same amount of useful heat.
Understand your estimate
How it works
Compare a gas boiler and a heat pump supplying the same useful heat. Seasonal mode compares a year of heating. It includes gas standing charges where the account remains. Published test-point mode compares only the heat you enter at those exact test conditions. It excludes standing charges and is not an annual estimate.
Use heating-only consumption, tax-inclusive prices and assessed equipment performance. Personal inputs start empty. The worked example is separate from your answers; it does not promise a saving for your home.
Start with gas use and boiler efficiency, or enter useful heat demand directly. Apply the chosen heat pump performance to that same demand. Then compare fuel costs and any gas standing charge that still applies.
A few good questions
Before youget started.
Understand this calculator, the figures to enter and the limits of your estimate.
Sources
- Energy price cap unit rates and standing chargesChecked on 9 October 2026
- Changes to energy price cap between 1 October and 31 December 2026Checked on 9 October 2026
- Energy Saving Trust: heat pump running costs and performanceChecked on 13 October 2026
- Vaillant: aroTHERM Split published technical tableChecked on 14 October 2026
- Last checked
- 21 October 2026
- Rates as of
- 1 October 2026
EnergySums
Heat pump vs gas boiler running costs
United Kingdom · How it works
- Guide updated
- 21 October 2026
- Rates as of
- 1 October 2026
| Item | Value |
|---|---|
| Guide updated | 21 October 2026 |
| Rates as of | 1 October 2026 |
How it works
Compare a gas boiler and a heat pump supplying the same useful heat. Seasonal mode compares a year of heating. It includes gas standing charges where the account remains. Published test-point mode compares only the heat you enter at those exact test conditions. It excludes standing charges and is not an annual estimate.
Use heating-only consumption, tax-inclusive prices and assessed equipment performance. Personal inputs start empty. The worked example is separate from your answers; it does not promise a saving for your home.
Start with gas use and boiler efficiency, or enter useful heat demand directly. Apply the chosen heat pump performance to that same demand. Then compare fuel costs and any gas standing charge that still applies.
Formula
Useful heat means heat delivered to your home, measured in kWh. For the annual comparison, enter it directly or use: annual heating gas (kWh) × (boiler efficiency ÷ 100). Leave out cooking and hot water unless they belong in the heating demand you are comparing.
Gas needed per year = useful heat (kWh) ÷ (boiler efficiency ÷ 100). Heat pump electricity per year = useful heat (kWh) ÷ seasonal performance (SCOP). COP means heat delivered divided by electricity used. SCOP measures that ratio over a season. A ratio of 4 means 4 kWh of heat per 1 kWh of electricity.
Multiply each energy amount by its matching unit price, dividing pence by 100 to get pounds. Yearly gas standing charge = 365 days × daily standing charge (p/day) ÷ 100 p/GBP. Add it only where the gas account remains open. Annual costs hold prices constant; real prices and conditions can change.
Higher seasonal performance uses less electricity and gives the lower heat pump cost. Both cost bounds come from your supplied scenarios; they do not predict cold-weather output. Convert percentages once: 90% = 90 ÷ 100 = 0.9. Enter COP or SCOP as a ratio. Monthly figures are yearly totals divided by twelve, rather than forecasts of winter bills.
Worked example
These illustrative inputs are separate from your saved answers. Prices, use and performance are held constant for this worked scenario; they are not personal defaults.
Inputs used in this worked example.
- Electricity price
- My bill rate
- Electricity unit price
- 26.32 p / kWh
- Gas price
- My bill rate
- Gas unit price
- 7.97 p / kWh
- Equipment performance source
- My assessed performance
- Gas standing charge
- 29.68 p / day
- Heating use entered as
- Gas on my bill
- Annual gas for heating
- 12000 kWh / year
- Boiler efficiency
- 90 %
- Lower seasonal heat pump efficiency
- 3 SCOP
- Higher seasonal heat pump efficiency
- 4 SCOP
- End the gas account completely
- Remove all gas
- Price conversion
- 100 pence or cents per currency unit
| Item | Value |
|---|---|
| Electricity price | My bill rate |
| Electricity unit price | 26.32 p / kWh |
| Gas price | My bill rate |
| Gas unit price | 7.97 p / kWh |
| Equipment performance source | My assessed performance |
| Gas standing charge | 29.68 p / day |
| Heating use entered as | Gas on my bill |
| Annual gas for heating | 12000 kWh / year |
| Boiler efficiency | 90 % |
| Lower seasonal heat pump efficiency | 3 SCOP |
| Higher seasonal heat pump efficiency | 4 SCOP |
| End the gas account completely | Remove all gas |
| Price conversion | 100 pence or cents per currency unit |
- Gas boiler / year
- £1,064.73
- Heat pump lower cost / year
- £710.64
- Heat pump higher cost / year
- £947.52
| Item | Value |
|---|---|
| Gas boiler / year | £1,064.73 |
| Heat pump lower cost / year | £710.64 |
| Heat pump higher cost / year | £947.52 |
- Useful heat / year
- 12,000 kWh gas × (90 ÷ 100)= 10,800 kWh heat/year
- Gas energy / year
- 10,800 kWh heat ÷ (90 ÷ 100)= 12,000 kWh gas/yearBoiler efficiency: 90%. The factor (90 ÷ 100) converts that percentage to a fraction.
- Gas energy cost / year
- 12,000 kWh × (7.97 p/kWh ÷ 100 p/GBP)= £956.40
- Gas standing charge / year
- 365 days × (29.68 p/day ÷ 100 p/GBP)= £108.33
- Gas total / year
- 956.4 GBP energy + 108.332 GBP standing charge= £1,064.73
- Heat pump electricity / year: lower cost
- 10,800 kWh heat ÷ 4= 2,700 kWh electricity/yearSCOP (seasonal coefficient of performance) 4 means 4 kWh of useful heat per 1 kWh of electricity over the season.
- Heat pump energy cost / year: lower cost
- 2,700 kWh × (26.32 p/kWh ÷ 100 p/GBP)= £710.64
- Heat pump total / year: lower cost
- 710.64 GBP electricity + 0 GBP retained gas standing charge= £710.64Gas standing charge removed because you selected ending the gas account.
- Heat pump electricity / year: higher cost
- 10,800 kWh heat ÷ 3= 3,600 kWh electricity/yearSCOP (seasonal coefficient of performance) 3 means 3 kWh of useful heat per 1 kWh of electricity over the season.
- Heat pump energy cost / year: higher cost
- 3,600 kWh × (26.32 p/kWh ÷ 100 p/GBP)= £947.52
- Heat pump total / year: higher cost
- 947.52 GBP electricity + 0 GBP retained gas standing charge= £947.52Gas standing charge removed because you selected ending the gas account.
| Calculation | Formula with saved values | Result |
|---|---|---|
| Useful heat / year | 12,000 kWh gas × (90 ÷ 100) | 10,800 kWh heat/year |
| Gas energy / year | 10,800 kWh heat ÷ (90 ÷ 100)Boiler efficiency: 90%. The factor (90 ÷ 100) converts that percentage to a fraction. | 12,000 kWh gas/year |
| Gas energy cost / year | 12,000 kWh × (7.97 p/kWh ÷ 100 p/GBP) | £956.40 |
| Gas standing charge / year | 365 days × (29.68 p/day ÷ 100 p/GBP) | £108.33 |
| Gas total / year | 956.4 GBP energy + 108.332 GBP standing charge | £1,064.73 |
| Heat pump electricity / year: lower cost | 10,800 kWh heat ÷ 4SCOP (seasonal coefficient of performance) 4 means 4 kWh of useful heat per 1 kWh of electricity over the season. | 2,700 kWh electricity/year |
| Heat pump energy cost / year: lower cost | 2,700 kWh × (26.32 p/kWh ÷ 100 p/GBP) | £710.64 |
| Heat pump total / year: lower cost | 710.64 GBP electricity + 0 GBP retained gas standing chargeGas standing charge removed because you selected ending the gas account. | £710.64 |
| Heat pump electricity / year: higher cost | 10,800 kWh heat ÷ 3SCOP (seasonal coefficient of performance) 3 means 3 kWh of useful heat per 1 kWh of electricity over the season. | 3,600 kWh electricity/year |
| Heat pump energy cost / year: higher cost | 3,600 kWh × (26.32 p/kWh ÷ 100 p/GBP) | £947.52 |
| Heat pump total / year: higher cost | 947.52 GBP electricity + 0 GBP retained gas standing chargeGas standing charge removed because you selected ending the gas account. | £947.52 |
Assumptions and limits
Use energy and efficiency figures that describe the same heating period. A maximum power rating, a measured average and yearly energy use are different quantities. The tool does not fill an empty field with a guessed power, efficiency or saving.
This compares entered fuel costs. Purchase, grants, installation payback, comfort and equipment capacity need separate checks. Remove the gas standing charge only if the account can close completely. Keeping gas for another use can mean that charge remains. Existing electricity standing charges are excluded.
Published model values apply only at the stated air and water temperatures, including humidity where recorded. Confirm the exact product against the linked maker table. The tool does not estimate values between test points or turn one test into seasonal performance. Changing water temperatures needs your own assessed performance.
Country rules
Published UK electricity prices use the selected Ofgem region and payment method. Published gas uses the Great Britain Direct Debit average. Stored prices include the tax treatment recorded for their period. Use your own tax-inclusive bill prices when those better match the intended comparison.
Check the source links and dates beside the prices. They identify the stored records, rather than verifying your home’s heating demand or proposed equipment. A checked guidance page explains the method; it does not supply missing product ratings or personal use.
When to ask a professional
Gas pipework and boiler removal require a Gas Safe registered engineer. Ask a competent heat pump installer to assess the property and whole system. They should check the heat demand, equipment output and installation requirements.
Bring heating bills, boiler efficiency and the proposed heat pump’s assessed seasonal performance. For test-point mode, bring the exact model and temperature table. Ask which assumptions match your home and which costs are outside this estimate. Follow the maker instructions and local rules.
Questions and answers
| Question | Answer |
|---|---|
| Are heat pumps more expensive to run than a gas boiler? | It depends on electricity and gas prices and seasonal heat pump performance. For the same useful heat, compare electricity price divided by SCOP with gas price divided by boiler efficiency, then account for any gas standing charge. |
| Which is cheaper to run, heat pump or gas? | The comparison uses your useful heat demand, fuel prices and chosen SCOP scenarios. Positive annual savings mean the heat pump has lower entered running costs; negative savings mean gas has lower entered running costs. |
| Should I replace my gas boiler with a heat pump? | Running cost is one part of that decision. Obtain an installation quote, a property assessment and a check of heat distribution and cold-weather output. Grants do not reduce annual energy consumption. |
| How much does it cost to run a heat pump per month? | Monthly figures are annual cost divided by 12, rather than a prediction of each winter bill. Annual heat pump electricity is useful heat divided by your chosen SCOP, multiplied by the electricity price; retained gas standing charges are then added. |
| Are heat pumps worth it? | Worth depends on installed cost, comfort, system suitability and running costs. This calculator compares user-supplied seasonal scenarios and does not calculate installation payback or recommend a replacement. |
Sources
| Source | Checked | Reference URL |
|---|---|---|
| Energy price cap unit rates and standing charges | 9 October 2026 | https://www.ofgem.gov.uk/information-consumers/energy-advice-households/get-energy-price-cap-standing-charges-and-unit-rates-region |
| Changes to energy price cap between 1 October and 31 December 2026 | 9 October 2026 | https://www.ofgem.gov.uk/news/changes-energy-price-cap-between-1-october-and-31-december-2026 |
| Energy Saving Trust: heat pump running costs and performance | 13 October 2026 | https://energysavingtrust.org.uk/heat-pump-questions-answered/ |
| Vaillant: aroTHERM Split published technical table | 14 October 2026 | https://professional.vaillant.co.uk/for-installers/products/arotherm-split-heat-pump-58752.html |