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Have you just recently switched to an air source heat pump to cut your energy costs, but found your electricity bill soaring high? You are definitely not the only one with that problem. Although heat pumps are renowned for their efficient use of energy for heating, some homeowners see unexpected costs.
There are many reasons why this might happen. Maybe your home is not insulated well enough, or your heat pump is working too hard when it’s cold. It might also be running too often or be set too high.
But you can fix most of these issues. Here is why your bill might be higher than expected and how to get the most out of your heat pump—without breaking the bank.
What are the Air Source Heat Pump Running Costs?
A UK air source heat pump’s running costs are usually between £700 and £1,550 per year. The cost will depend upon the size of your home, the level of insulation it has, and how intensively you use your hot water and your heating.
Although heat pumps are more efficient than traditional boilers, their costs can still be variable — not least with the rising price of electricity. Let’s break down what affects these costs.
Factors Impacting Heat Pump Running Costs
1. Thermostat Settings
The pump works harder when the thermostat is set too high. Keeping the temperature steady and comfortable — not constantly adjusting — helps control the amount of energy used.
2. Efficiency (Coefficient of Performance – CoP)
The CoP is used to measure the efficiency of a heat pump. If the CoP is 3, the pump provides 3 units of heat for 1 unit of electricity. The higher the value of the CoP, the lower the operating expenses.
3. Electricity Tariffs
As your heat pump is electricity-powered, the cost will be based on your tariff. Off-peak rates or time-of-use tariffs can save money by operating at cheaper times when you heat.
4. Insulation
A well-insulated house holds heat. If your house is draughty, the heat pump will have to work harder.
5. Heat demand
Larger homes or homes with high water usage for hot water require more energy. Which means a larger heat pump—and a higher operating cost.
6. Maintenance
A dirty heat pump or a non-maintained one will not operate properly. That means higher power and higher bills.
Check your Eligibility Now
If you are receiving benefits from the UK Government then you might be eligible for free insulation grants.
Heat Pump Electricity Consumption
Air source heat pumps are electricity powered, and the amount it will cost to run one will rely heavily on how much electricity you use and the prices at the time.
In the UK today as of 2024, electricity costs around 28.62p per unit with a standing daily charge of 53.35p. To give this context, gas costs 7.42p per unit with a standing daily charge of 29.60p.
In order to get a rough idea:
- A typical UK home (not fitted with a heat pump) uses around 2,700 kWh of electricity and 11,500 kWh of gas per year.
- That’s around £77 for electricity and £85 for gas — a total of around £162 a year (not including standing charges).
But with an air source heat pump, the numbers are different.
A typical heat pump:
- Uses around 9,653 kWh of heat per year to warm your home.
- At a 300% level of efficiency (or a CoP of 3), it uses around 3,218 kWh of electricity per annum.
- At the current cost of electricity, this is roughly £870 per year — somewhat more than the price of a gas boiler, which is roughly £820 per year.
Your total energy bill also relies on other factors including:
- Where you live (the fee differs by region)
- How well your home holds heat
- If you have a fixed or a smart tariff
- Daily standing fees for electricity and gas
Some suppliers—like Octopus—offer smart tariffs that make the cost of heat pumps cheaper. You can save about £85 a year by shifting your heat to off-peak hours. You will save a further £110 a year by disconnecting your gas supply and switching entirely to electricity.
In short, yes, it costs more—but heat pumps consume a great deal less. So the running cost overall isn’t as dreadful as it first appears.
Why is My Electric Bill so High with an Air Source Heat Pump?
If you have noticed a spike in your electricity bill since getting a heat pump, don’t worry—it’s a common concern. Here’s what might be going on.
1. Your Heat Pump Is Working Overtime When It’s Cold Outside
Air source heat pumps take heat from the outside air — but when temperatures drop close to the point where it freezes, the pump will have to work harder to extract heat. The colder the temperatures are, the harder the system performs.
When temperatures are low, your heat pump may kick into support (or backup) heat mode, which means using electric resistance heat. It is much less efficient and causes a spike in your electricity usage.
2. Poor Insulation
If your home is not well insulated, the heat escapes very fast. This results in your heat pump needing to work harder and using more electricity to heat the space. Loft insulation, cavity wall insulation, and double glazing all save money.
3. Heat Pump Size Isn’t Right for Your Home
If the heat pump is too small, it will not warm your home effectively, and will be running continuously and using too much electricity. The pump might also be too big and switch on and off too frequently, wasting power.
4. Electricity Is More Expensive Than Gas
Heat pumps take heat from the air and pump it into your home with the help of electricity. The problem? Electricity costs 28.62p per unit now, and gas costs 7.42p per unit.
So while the heat pump uses less energy than the gas boiler, the fact that electricity tends to be more costly means the bill may seem high.
5. Incorrect Thermostat Settings
Keeping your thermostat too high can put your heat pump into overdrive. Heat pumps operate best when the house is maintained at a consistent, middle-of-the-road level rather than warmed up from a cold house.
If the temperature is continuously changed or is too high, the pump will work longer and use more power.
6. Lack of Regular Maintenance
Heat pumps need regular maintenance to operate effectively. Clogged filters, blocked coils, and worn-out parts make the unit work harder and draw more energy.
7. Electricity Tariffs and Rising Energy Prices
This isn’t the heat pump’s fault. Electricity prices are also increasing in the UK and this can drive bills up. If you are on a standard variable tariff, price hikes will directly hit your bill — irrespective of the fact that your heat pump is working efficiently.
Running Costs of Heat Pump Vs Gas Boiler
Heat pumps are a bit higher priced to purchase, but ultimately save you money.
- Installing an air source heat pump usually costs between £8,000 and £18,000.
- A gas boiler is cheaper to install—between £3,500 and £7,000.
But once installed, heat pumps are cheaper to run. They are electricity-powered but are significantly more efficient than gas boilers. And that means more heat for the same level of energy.
Ground source heat pumps are costlier to install but are very efficient and quiet. They are also efficient when the temperatures are low.
If you intend to reside in your home for the long term, a heat pump can be a wiser, environmentally friendly investment.
How Much Does a Heat Pump Cost Per Hour?
A compact heat pump (around 2.2kW) costs around 54p per hour. It costs £4.31 for 8 hours.
An 11kW unit for a home with three bedrooms will cost around £2.69 per hour.
Keep also in mind that heat pumps are not running full-time. They are running steadily and heating your home with overall reduced amounts of energy.
Maintenance and Repair Costs for Heat Pumps
Heat pumps are reliable, but they must be maintained regularly.
- Maintenance costs around £100 to £200 a year.
- Minor repairs may range from £500 to £600
- Major work may be as expensive as £2,000
- Most heat pumps will last 10 to 15 years provided proper care is maintained.
Typical problems are:
- Frozen coils
- Fault compressors or sensors
- Electric problems
- Refrigerant leaks
An annual service of air source heat pump identifies issues before they arise and ensures things are running effectively.
7 Reasons Why Switching to a Heat Pump is a Smart Choice
Thinking about replacing your gas boiler with a heat pump? Here is why it is a smart move:
- Very efficient with energy: Heat pumps produce 3 to 4 units of heat for each unit consumed.
- Lower your bills for energy: Heat pumps are a better option than gas boilers. They are likely to cost more to install but save you money overall.
- Environmentally friendly heating: Heat pumps produce lower carbon emissions and decrease the carbon footprint of your home.
- Efficient all year round: They can heat your home in winter and cool it in summer. That’s two systems in one.
- Quieter than the boiler: They are 40–50 decibels — the same as the sound of a fridge — while the boiler is noisier.
- Grants from the government: You may qualify for a grant for the installation of a free air source heat pump.
- Pairs well with solar power: Heat pumps are even better when combined with solar panels and utilise clean energy to heat your home.
Tips to Lower Your Heat Pump Electricity Use
You’ll save gas by switching to a heat pump but may end up with a higher electricity bill. Don’t worry — the following heat pump efficiency tips will minimise your expenses:
1. Keep the temperature constant
Do not constantly change the thermostat. Set the thermostat to a level where you are comfortable and leave it alone. The steadier it stays, the less your heat pump will need.
2. Lower your water temperature
If your heat pump warms water too hot, it will use too much power. Get the water around 40°C — warm enough to warm your home.
3. Improve Home Insulation
Add insulation around the home to keep the heat inside. Consider:
- Double or triple-glazing windows to reduce heat loss.
- Cavity wall insulation (if your home has cavity walls) to stop heat from escaping.
- Loft insulation to stop heat from escaping through the roof.
- Keep your heat pump every year.
A heat pump not properly maintained can raise your bills by 25%. It functions optimally with proper maintenance.
4. Upgrade your heating system
Larger radiators or underfloor heating distribute the heat more effectively, so your pump doesn’t have to do as much work.
5. Switch to lower-cost electricity or go solar
Shop around for lower-cost electricity deals or install solar panels to power your heat pump with cheaper electricity.
The Bottom Line
A switch to a heat pump is a sensible and eco-friendly solution for your home. While the initial cost is more than for a gas boiler, heat pumps are far more efficient and pay for themselves with lower bills in the long term.
They are also compatible with solar panels and smart tariffs, cutting your bills further. They also reduce carbon emissions, making your home greener. With proper insulation and maintenance, a heat pump can heat your home without costing the earth.
Frequently Asked Questions
Not really. A heat pump would use around 4,000 kWh per annum. That’s roughly 333 kWh per month, varying with the season and your home.
Running costs are usually £700 to £1,550 per year. It’s lower than the running cost of a conventional gas boiler, which could be higher.
This may be due to poor insulation, high water temperatures, or improper maintenance. You should maintain and inspect it regularly for better performance.
Yes. Heat pumps are low-carbon and efficient and can lower your bills for heating—especially where your home is well-insulated.
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