Home Heat Pump Guide

Reducing Heat Pump Electricity Costs: 10 Tips

A heat pump is one of the most efficient ways to heat a UK home, but "efficient" does not automatically mean "cheap." Your electricity bill depends on how well the system is set up, how your home retains heat, and which tariff you are on. The good news is that most heat pump households have significant room to reduce their costs — often without spending a penny.

Here are ten practical, proven ways to lower your heat pump electricity bills, ranked roughly from easiest (and cheapest) to most impactful.

1. Lower Your Flow Temperature

Potential saving: 10% to 25% on heating electricity

This is the single most impactful free change you can make. Flow temperature is the temperature of the water your heat pump sends to your radiators or underfloor heating. The lower it is, the higher your COP and the less electricity you use.

Many systems are installed with the flow temperature set higher than necessary — sometimes 50°C or even 55°C — to guarantee comfort. But if your radiators can keep your rooms warm at 42°C or 45°C, you are wasting electricity by running hotter.

How to do it:

  • Drop the flow temperature by 2°C at a time
  • Wait 2 to 3 days at each setting to see if your rooms stay comfortable
  • Keep going until rooms start feeling cool, then go back up 2°C
  • Aim for the lowest flow temperature that keeps your home warm — typically 35°C to 45°C for most well-insulated homes

2. Enable Weather Compensation

Potential saving: 5% to 15% on heating electricity

Weather compensation is a control feature built into most modern heat pumps. It uses an outdoor temperature sensor to automatically adjust the flow temperature — running cooler when it is mild outside and warmer when it is cold. This means the system is always operating at the most efficient flow temperature for the current conditions, rather than running at a fixed, often unnecessarily high temperature.

How to do it:

  • Check if your outdoor sensor is installed and connected (it should have been fitted during installation)
  • Enable weather compensation in your heat pump's settings (check the manufacturer's manual or app)
  • Your installer can set the "heating curve" — the relationship between outdoor temperature and flow temperature — to match your home's heat loss profile

If your installer did not set up weather compensation, ask them to. It is one of the most important features for efficient operation.

3. Switch to a Time-of-Use Electricity Tariff

Potential saving: 15% to 30% on total electricity bill

A time-of-use tariff charges different rates at different times of day. By shifting as much heat pump consumption as possible to the cheapest periods, you pay less for the same amount of electricity.

The best options in 2026 include:

  • Octopus Cosy: Specifically designed for heat pumps, with three cheap-rate windows per day
  • Octopus Agile: Half-hourly pricing based on wholesale rates — great if you can be flexible about when you heat
  • Octopus Go / Intelligent Go: Very cheap overnight rate, reasonable daytime rate — especially good if you also have an EV

You will need a SMETS2 smart meter for these tariffs. If you do not have one, request it from your supplier — it is free.

4. Improve Your Home's Insulation

Potential saving: 15% to 40% on heating electricity

The less heat your home loses, the less your heat pump needs to replace. Insulation improvements have a direct, permanent impact on your electricity consumption. The best investments, in rough order of cost-effectiveness:

  • Draught-proofing (£50 to £300): Seal gaps around doors, windows, letterboxes, and loft hatches. Cheap and immediately effective.
  • Loft insulation top-up (£300 to £600): If your loft has less than 270mm of insulation, topping it up is one of the best returns you can get.
  • Cavity wall insulation (£500 to £1,500): If your walls have unfilled cavities, this is a no-brainer — it pays for itself within a few years.
  • Window upgrades (£3,000 to £8,000): Replacing single glazing with double or triple glazing makes a significant difference but is expensive. Consider if your windows are due for replacement anyway.
  • Solid wall insulation (£5,000 to £15,000+): The most expensive option, but for homes with uninsulated solid walls, it can reduce heat loss by 30% to 40%.

Better insulation also allows you to run your heat pump at a lower flow temperature (see tip 1), which compounds the savings.

5. Set the Right Room Temperature

Potential saving: 8% to 10% per degree reduced

Every degree Celsius you lower your thermostat reduces your heating electricity consumption by roughly 8% to 10%. This is one of the simplest and most immediate savings available.

  • The NHS recommends a minimum of 18°C for healthy adults and 21°C for elderly or vulnerable people
  • Many people heat to 21°C or 22°C when they would be comfortable at 19°C or 20°C with appropriate clothing
  • Consider setting different temperatures for different rooms — bedrooms can often be 2°C to 3°C cooler than living areas

With a heat pump, it is more efficient to maintain a slightly lower, consistent temperature than to set a high target and then turn the heating off. A steady 19°C uses less electricity than cycling between 16°C and 22°C.

6. Install Solar Panels

Potential saving: £250 to £500 per year on heat pump electricity

Solar panels generate free electricity during daylight hours, directly offsetting the electricity your heat pump draws from the grid. A typical 4 kWp system can cover 20% to 35% of your heat pump's annual consumption, rising to 40% to 55% with a battery.

The solar-heat pump combination works best if you:

  • Programme your heat pump to boost heating during midday when solar generation peaks
  • Heat your hot water during solar hours rather than overnight
  • Use a solar diverter or battery to capture excess generation

Solar panels cost £5,000 to £7,000 for a 4 kWp system (VAT-free for residential installations) and typically pay for themselves in 7 to 12 years. Visit Home Solar Guide for detailed information on solar panel installation.

7. Optimise Your Hot Water Schedule

Potential saving: 5% to 10% on total heat pump electricity

Hot water heating accounts for 15% to 30% of your heat pump's total electricity consumption. Optimising when and how it heats your cylinder can make a noticeable difference.

  • Heat once per day: A well-insulated cylinder only loses 1°C to 2°C over 24 hours. One heating cycle per day is usually sufficient for most households.
  • Time it right: If you have solar panels, heat the cylinder at midday. If you are on a time-of-use tariff, heat overnight during the cheap window.
  • Lower the target temperature: 50°C is sufficient for most households (with a periodic Legionella cycle to 60°C once a week). Running the cylinder at 55°C or 60°C routinely wastes electricity.
  • Insulate the cylinder: If your cylinder does not have factory-fitted insulation to current standards, an insulation jacket (£15 to £30) reduces heat loss and the need for reheating.

8. Use Smart Controls and Scheduling

Potential saving: 5% to 15% on heating electricity

Heating rooms you are not using or at times when you are not home wastes electricity. Smart controls help you heat only when and where needed.

  • Room thermostats: Set individual temperatures for each room if your system supports zone control. Heat the living room to 20°C but keep spare bedrooms at 16°C.
  • Programmable schedules: Set the heat pump to reduce output overnight and during work hours, then raise it for when you are home.
  • Smart thermostats: Devices like Hive, tado°, or Nest learn your patterns and adjust automatically. Some can detect when you leave the house and reduce heating.
  • Do not switch off completely: With a heat pump, a gentle setback (reducing by 2°C to 3°C) is more efficient than switching off and reheating from cold.

9. Keep the Outdoor Unit Clear and Maintained

Potential saving: 2% to 5% on heating electricity

Your air source heat pump's outdoor unit needs a steady supply of air to extract heat efficiently. Anything that restricts airflow forces the fan to work harder and reduces the COP.

  • Clear vegetation: Keep plants, hedges, and shrubs at least 300mm from the unit on all sides
  • Remove debris: Clear leaves, cobwebs, and any accumulated dirt from the fan grille and coils
  • Do not box it in: Decorative screens or fencing that restrict airflow reduce performance. If you must screen the unit, ensure generous clearance
  • Annual service: A professional service checks refrigerant levels, cleans coils, and ensures all components are working efficiently. Cost: £100 to £200 per year.

10. Consider Battery Storage for Tariff Arbitrage

Potential saving: £400 to £750 per year (on a time-of-use tariff)

If you are on a time-of-use tariff, a home battery lets you charge at cheap overnight rates and discharge during expensive peak periods. With a heat pump using 15 to 25 kWh per day in winter, the daily savings from tariff arbitrage add up quickly.

A 10 kWh battery costs £3,000 to £5,000 and can pay for itself in 4 to 7 years through tariff savings alone. If you also have solar panels, the battery stores excess daytime generation for evening use, further reducing grid dependence.

This tip is last on the list because it requires upfront investment and is most effective when combined with the other tips above. Get the free and low-cost changes right first, then consider a battery once your system is running efficiently.

Putting It All Together: What Can You Save?

Let us apply these tips to a real-world example. Consider a 3-bed semi with an 8 kW heat pump currently spending £1,200 per year on heat pump electricity.

  • Lower flow temperature (free): Save 15% = £180
  • Enable weather compensation (free): Save 10% = £120
  • Switch to Octopus Cosy (free): Save 20% = £240
  • Drop thermostat 1°C (free): Save 8% = £96
  • Optimise hot water schedule (free): Save 5% = £60

These five free changes alone could reduce the bill from £1,200 to approximately £500 to £700 per year. The savings are not purely additive (some overlap), but the total impact of implementing all of them is significant — potentially cutting costs by 40% to 50%.

Add insulation improvements, solar panels, and a battery, and you could bring costs below £400 per year — though these require upfront investment.

Frequently Asked Questions

Which tip makes the biggest difference?

For most homes, the combination of lowering flow temperature and switching to a time-of-use tariff delivers the largest savings. These two changes alone can reduce costs by 25% to 40% with zero upfront investment.

Can I make these changes myself or do I need an installer?

Tips 3, 5, 7, 8, and 9 are entirely DIY. Tips 1 and 2 may need your installer's help the first time (to adjust settings and the heating curve). Tips 4, 6, and 10 require professional installation. Your heat pump's manufacturer app often allows you to adjust flow temperature and scheduling yourself once you know what you are doing.

Will reducing the flow temperature make my house cold?

Only if you reduce it too far. Lower the temperature gradually (2°C at a time) and monitor comfort over several days. If your radiators are large enough, you may find you can run at 40°C without any noticeable difference in room temperature. If rooms do get cold, go back up — or consider upgrading the radiators in the affected rooms.

How quickly will I see the savings?

Free changes (flow temperature, weather compensation, tariff switch, thermostat adjustment) show results immediately — within your next electricity bill. Insulation improvements take effect as soon as they are installed. Solar panels and batteries have a payback period of several years before the cumulative savings exceed the upfront cost.

What if my heat pump is already running efficiently?

If your SCOP is above 3.5, your flow temperature is below 45°C, and you are on a time-of-use tariff, you are already doing well. Focus on insulation, solar panels, and behavioural changes (thermostat settings, scheduling) for further savings. There is always room for incremental improvement, even in well-optimised systems.

The Bottom Line

There is no single magic trick to slashing heat pump electricity costs. The biggest savings come from combining multiple small improvements — lower flow temperatures, weather compensation, smart tariffs, good insulation, and sensible scheduling. The best part is that many of these are completely free.

Start with the free changes and work your way through the list. Even implementing just the top three tips can transform your heat pump from "about the same cost as gas" to "noticeably cheaper than gas" — which is exactly where this technology should be.