How to Reduce Heat Pump Running Costs | UK Guide 2026
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Quick Answer: How Can You Reduce Heat Pump Running Costs?
The most effective ways to reduce heat pump running costs are to use the lowest practical heating flow temperature, enable properly configured weather compensation, avoid unnecessarily large thermostat setbacks, check hot-water and immersion-heater settings, and choose an electricity tariff that suits heat-pump use.
You can also cut the amount of heat the system needs to produce by improving insulation and draught-proofing.
If some rooms only become warm when the flow temperature is raised significantly, the problem may be insufficient radiator output rather than the heat pump itself. In that situation, upgrading selected radiators can allow the whole system to operate more efficiently.
Energy Saving Trust recommends steady operation, appropriate heating curves, lower flow temperatures and suitable tariffs as important efficiency measures.
How to Reduce Your Air Source Heat Pump Running Costs
If your air source heat pump costs more to run than expected, replacing the unit is rarely the first thing to consider. Running costs depend on three broad factors: how much heat your home needs, how efficiently the heat pump produces that heat, and how much you pay for electricity.
That means the most effective way to reduce heat pump running costs is usually to improve one or more of those three areas.
For many households, the first checks should be the heating flow temperature, weather compensation settings, electricity tariff, hot-water controls and whether the home can stay comfortable without excessive heat loss. Radiator sizing, system balancing and unnecessary use of direct electric backup heating can also make a substantial difference.
This guide is for UK homeowners who already have an air source heat pump and want practical ways to lower electricity costs without sacrificing comfort.
If you are still comparing systems rather than troubleshooting an existing installation, you can also compare heat-pump quotes for your property.
Which Changes Can Reduce Heat Pump Running Costs?
| Action | Why it can reduce costs | First step |
|---|---|---|
| Lower flow temperature | Helps the compressor work more efficiently | Reduce gradually while checking comfort |
| Optimise weather compensation | Automatically lowers water temperature in milder weather | Check the heating curve |
| Use steadier heating | Avoids repeated high-temperature recovery periods | Use small rather than extreme setbacks |
| Review hot-water settings | Reduces unnecessary high-temperature operation | Check schedules and immersion use |
| Change electricity tariff | Can lower the price paid per kWh | Compare heat-pump and time-of-use tariffs |
| Reduce heat loss | Your heat pump has less heating work to do | Target insulation and draughts |
| Improve radiator output | Can allow lower system temperatures | Identify rooms requiring high temperatures |
| Service or recommission | Can reveal control, flow or component problems | Investigate abnormal consumption |
1. First, Work Out Why Your Heat Pump Is Expensive to Run
Do not start changing settings simply because one winter electricity bill looks high.
A colder month naturally requires more heating. Your household may also be using more hot water or electricity elsewhere.
Instead, look at your heat pump’s electricity consumption over several weeks and compare it with outdoor conditions and indoor comfort.
There are only three fundamental ways to lower the bill:
- reduce the amount of heat your property needs;
- produce each unit of heat using less electricity; or
- pay less for the electricity you use.
This distinction matters. Switching tariff can lower your bill without improving heat-pump efficiency, while insulation can reduce electricity consumption even if the heat pump’s efficiency remains unchanged.
For a detailed explanation of the underlying cost calculation, see our guide to air source heat pump running costs.
2. Use the Lowest Practical Flow Temperature
Flow temperature is the temperature of the water leaving the heat pump for your radiators or underfloor heating.
It has a major influence on electricity consumption.
An air source heat pump extracts heat from outdoor air using refrigerant. Its compressor then raises that heat to a useful temperature. The larger the temperature increase required, the harder the compressor has to work.
Therefore, supplying 40°C water will normally require less electricity than supplying 55°C water, provided 40°C is still enough to heat the property.
Many UK radiator systems can operate somewhere around 35–45°C during at least part of the heating season, although the correct temperature is property-specific.
Do not simply enter the controller and dramatically reduce the temperature. Lower it gradually and check whether every room still reaches its target temperature during colder weather.
For more detail on seasonal performance and CoP, see our guide to air source heat pump efficiency.
3. Make Weather Compensation Work Properly
A fixed high flow temperature wastes one of a heat pump’s biggest efficiency opportunities.
Weather compensation adjusts heating-water temperature according to outdoor conditions. When it becomes milder outside, your home loses less heat, so the heat pump can usually send cooler water through the heating system.
When temperatures fall, it automatically increases the flow temperature.
MCS guidance requires weather compensation to be available on space-heating systems, although the correct heating curve depends on the property and emitters.
A poorly adjusted curve may leave the house unnecessarily hot or force the heat pump to operate at higher temperatures than necessary.
Our separate guide to heat pump weather compensation explains this control in more detail.
4. Do Not Operate It Like a Traditional Boiler
Gas boilers often heat a home using short periods of relatively hot water.
Heat pumps generally favour a different approach: longer operating periods at lower temperatures.
Energy Saving Trust advises keeping a steadier temperature and running the heat pump for longer periods rather than repeatedly allowing the property to cool substantially and then demanding rapid reheating. Energy Saving Trust’s heat-pump efficiency guidance
A modest overnight setback may work well in some homes. Large temperature drops are less predictable because the system may then need higher flow temperatures or backup heating to recover quickly.
The right strategy depends on your property’s heat loss, thermal mass and controls.
5. Check Hot Water and the Immersion Heater
Domestic hot water normally requires a higher temperature than space heating. Consequently, cylinder heating can operate at a lower CoP than normal room heating.
Check whether your cylinder is reheating more often than necessary and whether the immersion heater is running routinely.
An immersion heater converts electricity directly into heat rather than using the heat pump’s refrigeration cycle. It therefore uses substantially more electrical input for the same amount of delivered heat.
However, do not disable hygiene or Legionella protection without checking the manufacturer’s instructions or speaking with a competent engineer.
Scheduling normal hot-water heating sensibly can also help if you have cheaper electricity periods.
6. Check Whether You Are on the Right Electricity Tariff
Improving efficiency reduces the number of kWh your heat pump consumes. A better tariff reduces what those kWh cost.
Both matter.
Energy Saving Trust’s 2026 research modelled more than one million combinations of heat pumps, tariffs and other low-carbon technologies. It found that heat-pump users on suitable smart tariffs could save around £330 a year compared with those who were not using them in the scenarios modelled. Read Energy Saving Trust’s tariff research
Do not choose a tariff simply because it advertises a very cheap overnight rate. Check the expensive periods too.
Consider:
- when your heat pump normally consumes electricity;
- when your cylinder reheats;
- whether your home can comfortably shift some demand;
- peak-rate prices;
- standing charges; and
- your household’s other electricity consumption.
As of September 2026, Ofgem’s average capped Direct Debit electricity rate is 26.11p/kWh. From 1 October 2026, the average rises to 26.32p/kWh. Actual rates vary by region and tariff. Check the current Ofgem price-cap rates
7. Reduce the Amount of Heat Your Home Loses
A heat pump cannot avoid replacing heat that escapes through the building.
Loft, wall and floor insulation, better glazing and sensible draught-proofing can therefore reduce heating demand.
This does not automatically increase the heat pump’s thermodynamic CoP. Instead, your home simply needs fewer kWh of heat.
There can be a second benefit. Lower heat loss may allow rooms to stay comfortable at a lower flow temperature, which can improve heat-pump efficiency as well.
MCS emitter guidance demonstrates this relationship: reducing room heat loss can allow a heating system to operate at lower water temperatures.
8. Check Whether Your Radiators Are Forcing the Temperature Up
If most rooms are comfortable at a low flow temperature but one or two remain cold, increasing the temperature for the entire house can be an expensive solution.
The better answer may be larger or higher-output radiators in those particular rooms.
A radiator designed around hotter boiler water produces less heat when operated at heat-pump temperatures. Increasing its surface area can restore the required output without forcing the whole system to run hotter.
MCS heat-pump design standards require room-by-room heat-loss calculations because system sizing and emitter performance need to reflect the home’s actual heating requirement.
Underfloor heating often suits heat pumps well because its large surface area can deliver useful heat at relatively low water temperatures.
9. Monitor Performance Instead of Guessing
If your controller or monitoring system provides the information, track both electricity consumed and heat produced.
Their relationship tells you far more than the electricity bill alone.
Also record:
- outdoor temperature;
- indoor temperature;
- flow temperature;
- hot-water use;
- backup or immersion-heater operation; and
- any changes you make.
Change one setting at a time where practical. Otherwise, you will not know what actually improved performance.
Avoid judging an adjustment from a single day. Weather conditions can overwhelm relatively small efficiency improvements.
10. When High Running Costs Need an Engineer
Some problems cannot be solved through household settings.
Arrange a professional check if electricity consumption seems persistently excessive, rooms remain cold despite high flow temperatures, the heat pump cycles on and off unusually frequently, backup heating runs far more than expected, or the system displays repeated warnings.
A competent engineer can check system flow rates, hydraulic balancing, controls, sensors, commissioning settings and the heat pump itself.
Regular maintenance also helps identify problems before they become expensive. See our guide to air source heat pump servicing.
High Bills: What Should You Check First?
| What you notice | Possible issue | Practical next check |
|---|---|---|
| Home is warm but electricity use is high | Flow temperature or tariff | Check heating curve and electricity price |
| Some rooms stay cold | Emitter sizing or balancing | Compare radiator output room by room |
| Heat pump frequently stops and starts | Controls, flow or sizing | Ask for system performance review |
| Electricity spikes during hot-water heating | Immersion or cylinder settings | Review schedules and backup heater |
| Costs rise sharply only in cold weather | Higher heat demand or inefficient settings | Check flow temperature and backup operation |
| System always uses a high fixed temperature | Weather compensation may need adjustment | Review heating curve |
What Should You Change First?
Start with changes that cost little or nothing.
Check your tariff, understand your current flow temperature, confirm weather compensation is operating and inspect your hot-water schedules. Then see whether selected radiator or fabric improvements could allow the system to run cooler.
Do not buy solar panels, batteries or replacement heating equipment purely to compensate for a heat pump that has never been properly optimised.
First make the existing heating system work as efficiently as the property allows.
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Frequently asked questions
Find clear answers to common questions about air source heat pump running costs, flow temperature, weather compensation, tariffs, radiators, insulation, underfloor heating, immersion heaters, servicing and seasonal efficiency.
Check your flow temperature, weather compensation and electricity tariff first. These changes can often be reviewed without major building work.
Usually, yes. Lower flow temperatures generally improve heat-pump efficiency, provided your radiators or underfloor heating can still keep every room warm.
There is no universal setting. Many systems operate efficiently around 35–45°C for part of the year, but the correct temperature depends on heat loss, weather and emitter sizing.
Long operating periods are normal. Heat pumps often work efficiently by maintaining a steady indoor temperature rather than repeatedly reheating a cold home.
Not necessarily. A small setback may suit some properties, while a large overnight temperature drop can create a demanding morning recovery period.
Weather compensation automatically adjusts heating-water temperature according to outdoor temperature. It can help your heat pump avoid producing unnecessarily hot water during milder weather.
Possible causes include high heat demand, excessive flow temperature, poor controls, unsuitable radiators, frequent immersion-heater use, cold weather or an expensive tariff.
They can. Higher-output radiators may allow the property to remain comfortable at a lower flow temperature, improving heat-pump efficiency.
Yes. Insulation reduces heat loss, so the heat pump needs to produce less heat. It may also make lower flow temperatures practical.
It can be an efficient combination because underfloor heating offers a large emitter area and often operates at lower water temperatures. Actual costs still depend on heat demand and tariff.
Potentially. Energy Saving Trust's 2026 modelling found meaningful savings for heat-pump households using suitable smart tariffs, although results depend on consumption and tariff structure.
That can make sense on a tariff with cheaper overnight electricity. However, the best schedule depends on your household's hot-water use and tariff periods.
Frequent immersion-heater operation can materially increase electricity use because it uses direct resistance heating. Some immersion operation may still be required for system or hygiene purposes.
Long operating periods can be completely normal, particularly in colder weather. Frequent stopping and starting can sometimes be more concerning than continuous low-output operation.
Running costs generally rise in colder weather because your home loses more heat and air-source efficiency usually falls. Occasional defrost cycles are also normal.
Servicing will not automatically reduce bills, but it can identify faults, control problems or maintenance issues that are harming system performance.
Where monitoring allows, compare useful heat delivered with electricity consumed over a meaningful period. Seasonal performance gives a better picture than a single day's COP.
Not before investigating settings, tariff, emitters, heat loss and commissioning. High bills can result from the wider heating system rather than the heat-pump unit itself.
Conclusion
To reduce heat pump running costs, focus on the three things that actually determine the bill: heat demand, system efficiency and electricity price.
For many households, lower flow temperatures, correctly configured weather compensation, steady heating, sensible hot-water settings and an appropriate tariff provide the best starting point.
If the property still needs unusually high temperatures, investigate heat loss, radiator output and system commissioning rather than simply accepting a larger electricity bill.
The aim is not to make the house colder. It is to deliver the comfort you need using as little expensive electrical input as practical.
