If your heat pump isn’t performing as efficiently as it should — or you just want to make sure you’re getting the best possible SCOP from your system — these 10 practical tips are the most impactful changes you can make. Some cost nothing. A few require a small investment. All are grounded in how heat pumps actually work rather than vague advice about “setting your thermostat correctly”. We’ll tell you exactly what to do, why it works, and roughly how much you can expect to save by maximising your heat pump efficiency in a typical UK home.
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How much can these tips actually save?
Before diving into the individual tips, here’s a realistic summary of the potential savings on a 3-bed semi with 16,500 kWh annual heat demand, electricity at 25p/kWh (standard cap), currently running at SCOP 2.5:
| Tip | Typical SCOP improvement | Estimated annual saving (3-bed semi) | Cost to implement |
|---|---|---|---|
| Lower flow temperature to 45°C | +0.3 to +0.6 | £150–£300 | Free (settings change) |
| Run continuously (not on/off) | +0.2 to +0.4 | £80–£180 | Free |
| Enable weather compensation | +0.2 to +0.5 | £100–£250 | Free (if supported) |
| Loft insulation (if missing) | +0.1 to +0.3 indirect | £100–£200 + less heat demand | £200–£400 |
| Switch to Octopus Cosy tariff | N/A (tariff saving) | £200–£450 | Free |
| Upgrade undersized radiators | +0.3 to +0.6 | £150–£300 | £500–£1,500 |
| Annual service and calibration | +0.1 to +0.3 | £50–£150 | £100–£200/year |
| Fix hot water schedule | N/A (tariff saving) | £50–£150 | Free |
| Add buffer tank (if cycling) | +0.2 to +0.4 | £80–£180 | £400–£800 installed |
| Settings review with installer | +0.1 to +0.5 | £50–£250 | £100–£200 one-off |
Combining several of the free tips — lower flow temperature, continuous operation, weather compensation, and a tariff switch — could realistically save £400–£800 per year on a poorly configured system at no cost whatsoever. That’s not a typo. Configuration often matters more than hardware. Savings vary depending on property size, insulation, and energy tariff.
Tip 1: Lower your flow temperature to 40–45°C
Flow temperature — the temperature at which the heat pump sends hot water to your radiators — is the single biggest lever on SCOP. Every 5°C reduction in flow temperature adds roughly 0.3–0.5 to your seasonal efficiency figure.
Most heat pumps are commissioned by installers at 50–55°C because it’s a “safe” setting that will heat every room regardless of whether the radiators are right-sized. The problem is that running at 55°C turns a SCOP 3.5 system into a SCOP 2.5 one — the same electricity input produces significantly less heat per unit.
What to do: Ask your installer to lower the flow temperature to 45°C and monitor your home temperature for a week. If it stays warm enough, try 40°C. If rooms are cold, it means your radiators need upgrading (Tip 6) before you can lower the flow temperature fully. The target to aim for is a flow temperature below 45°C at an outdoor temperature of 0°C.
Tip 2: Run the heat pump continuously, not on and off
The instinct from gas boiler habits is to turn heating off overnight and when you leave the house. With a heat pump, this is often counterproductive. Heat pumps are most efficient running at low intensity for long periods — they use more electricity reheating a cold home from scratch than they would have used maintaining a steady temperature.
The reason is physics: the bigger the temperature difference between your indoor water circuit and the outdoor air, the harder the compressor works and the lower its COP. A system running at 38°C flow at 2°C outdoor is working gently. The same system starting from cold on a -3°C morning needs to run at 50°C to catch up — much less efficient.
What to do: Set your thermostat to a minimum overnight temperature of 16–17°C rather than off. Allow the heat pump to run in “setback” mode — maintaining a lower background temperature — rather than cycling completely off. Most modern heat pump controllers support this natively. You may see a slightly higher standing electricity draw overnight, but lower peak demand during the morning heat-up. The net result is almost always lower total electricity consumption.
Tip 3: Enable weather compensation
Weather compensation is one of the most underused features on UK heat pumps. It automatically adjusts the flow temperature based on the outdoor temperature: on a mild 12°C day, the flow temperature drops to 35°C; on a cold -3°C day, it rises to 50°C. This means the heat pump is always running at the lowest possible flow temperature for the conditions — maximising efficiency.
All major UK heat pumps support weather compensation: Vaillant Arotherm+ (via sensoAPP or sensoNET), Mitsubishi Ecodan (via MELCloud or FTC6 controller), Daikin Altherma 3 (via Daikin Residential Controller), Samsung EHS (via SmartThings or dedicated controller). Some systems ship with it disabled by default — check your controller settings or ask your installer.
What to do: Log into your heat pump’s app or controller and check whether weather compensation is enabled. If not, enable it and set the “heating curve” — the relationship between outdoor temperature and flow temperature. Your installer or the manufacturer’s commissioning guide will have recommended settings for your home type. Start with their recommendation and adjust gradually.
Tip 4: Insulate your home before or alongside installation
Insulation reduces heat demand, which directly reduces the electricity your heat pump needs to consume. But it also indirectly improves SCOP, because a well-insulated home can be heated with lower flow temperatures — the same thermal output at a lower temperature difference is less work for the compressor.
The highest-impact, lowest-cost insulation measures for most UK semi-detached homes are:
- Loft insulation to 270mm — typically £200–£400 DIY or subsidised, saves 15–25% of heating energy
- Cavity wall insulation — typically £300–£600 professionally installed, saves 15–20% for a semi-detached with unfilled cavities
- Draft-proofing doors and windows — typically under £100 DIY, immediate impact on cold spots
Check whether your home is eligible for ECO4 funding, which can pay for insulation measures at no cost for lower-income households. The Energy Saving Trust’s insulation guide has up-to-date subsidy information for England, Wales, and Scotland.
Tip 5: Upgrade radiators for the lower flow temperature
This is the tip that makes all the other tips possible. If your radiators were sized for a gas boiler at 70°C, they won’t deliver enough heat at 45°C — they’ll be cold or just warm to the touch. The solution is to upgrade the smallest or coldest radiators to larger ones.
You don’t necessarily need to replace all of them. A heat loss calculation will tell you which rooms are closest to their heat loss threshold, and those are the ones to prioritise. Double panel convector radiators (K2 type) offer about double the output of single panel models at the same size — a K2 replacement can double a radiator’s output for £100–£200 per room.
Our heat pump radiators guide covers how to size radiators for low-temperature operation and which brands are worth considering.
Tip 6: Switch to a smart heat pump electricity tariff
This doesn’t improve your SCOP, but it dramatically reduces what you pay for each kWh of electricity your heat pump consumes. On Octopus Cosy, off-peak electricity (4–7am and 1–4pm) is roughly half the standard price cap rate. Intelligent Octopus Go offers cheap electricity overnight. E.ON Next Drive offers a flat EV/heat pump rate.
To make the most of these tariffs, your heat pump needs to pre-heat during cheap periods and coast through peak hours. This works best with a controller that can schedule operation by time-of-day. The Homely controller is specifically designed for this — it integrates with Octopus Energy APIs to automatically optimise your heat pump schedule around cheap tariff windows.
Estimated saving: £200–£450 per year on a 3-bed semi versus a standard electricity tariff, with no change to SCOP or heat pump settings. Simply being on the right tariff and scheduling correctly is the easiest money you can save.
Tip 7: Service your heat pump annually
A heat pump that hasn’t been serviced gradually loses efficiency due to dirty coils, low refrigerant charge, and miscalibrated controls. Unlike a gas boiler where an annual service is legally required for landlords, heat pump servicing is recommended but not mandated — which means it often gets skipped.
A proper annual service by an MCS-certified heat pump engineer should include: cleaning the outdoor coil, checking refrigerant pressure and charge, verifying all sensor readings, checking controls calibration, and reviewing the controller settings for any obvious inefficiency. Expect to pay £100–£200 for a thorough service.
The payback is almost immediate: a dirty coil alone can reduce SCOP by 0.2–0.3, which on a 3-bed semi at 25p/kWh is £100–£150/year in wasted electricity. The service pays for itself within a year in most cases.
Tip 8: Set your hot water schedule correctly
Domestic hot water production is less efficient than space heating for a heat pump, because it requires water heated to 55–60°C rather than 35–45°C. The COP for hot water production is typically 1.8–2.5 versus 3.0–4.0 for space heating at the same ambient temperature.
Two scheduling mistakes cost money: running hot water heat-up during peak tariff hours, and running the hot water setpoint too high as a permanent setting (60°C continuous instead of 55°C with a weekly 60°C legionella cycle).
What to do: Schedule your hot water heat-up for the cheapest tariff period (4–7am on Octopus Cosy). Set the cylinder to 55°C as the normal setpoint, with a once-weekly pasteurisation cycle at 60°C. Do not run the cylinder at 60°C permanently — it reduces efficiency significantly with minimal additional safety benefit above 55°C for household use.
Tip 9: Add a buffer tank if your system is cycling
Short cycling — where the heat pump starts, runs briefly, stops, and starts again frequently — damages efficiency and accelerates compressor wear. It typically happens when the heating system volume is too small relative to the heat pump’s minimum output, which causes the system temperature to rise quickly and trigger the high-temperature limit.
The fix is a buffer tank — a small insulated vessel (typically 50–100 litres) added to the heating circuit that increases the water volume and smooths out demand spikes. Cost installed: typically £400–£800 including labour. More detail on when and why to use one in our buffer tank guide.
Signs your system may be cycling: the heat pump starts and stops more than once every 10–15 minutes in mild weather; you can hear the compressor starting up frequently; your electricity consumption shows short spikes rather than a steady draw.
Tip 10: Review your settings with your installer once per winter
Heat pump settings drift. Thermostats go out of calibration. Weather compensation curves get adjusted and forgotten. Hot water schedules get changed to work around a shower habit and never changed back. A one-hour annual review with your installer — ideally in November before serious cold weather arrives — costs £100–£200 and is one of the best investments you can make in your system’s long-term performance.
Ask them specifically to check: the weather compensation curve, the flow temperature at current outdoor conditions, the hot water schedule and setpoint, whether any fault codes have been logged, and whether the refrigerant pressure is within specification. If your installer doesn’t offer this as a service, ask at the point of installation that they include a first-winter check-in.
Where to start: a priority order
If you’re reading this because your heat pump bills are higher than expected, here’s the order we’d tackle it:
- First, free actions: Check whether weather compensation is enabled. Check your flow temperature setting and try lowering it by 5°C. Review your hot water schedule. Switch to Octopus Cosy if you haven’t.
- Second, low-cost actions: Book an annual service. Check for short cycling behaviour.
- Third, investment actions: Upgrade undersized radiators. Add loft insulation if you haven’t. Consider a buffer tank if cycling is confirmed.
Most people who implement the first category alone see a meaningful improvement within the first month. The combination of lower flow temperature, weather compensation, continuous operation, and a good tariff accounts for the majority of the gap between a poor-performing and a well-performing installation.
For a full breakdown of how running costs vary with SCOP and tariff choice, see our heat pump running costs guide and the efficiency explainer. If you’re running solar panels, pairing them with a heat pump that can use daytime excess generation is another strong efficiency move — SolarBlog has a detailed guide to the solar and heat pump combination.