Don’t Turn Your Heat Pump Off and On
One of the most common mistakes is treating a heat pump like a gas boiler — switching it off when you leave the house and cranking it up when you return. Heat pumps are designed for continuous low-temperature operation. Keeping the system running at a consistent, moderate temperature is far more efficient than frequent cycling. A setback of 2–3°C when away is fine; turning off completely is not.
Use Weather Compensation
Most modern heat pumps include a weather compensation feature that automatically adjusts the flow temperature based on the outside temperature. In cold weather, the system raises the flow temperature; in mild weather, it lowers it. Ensure this feature is enabled — it can reduce running costs by 10–20%.
Don’t Panic About the Defrost Cycle
During cold, humid weather, your outdoor unit will periodically defrost itself. You may notice:
- The unit appears to be producing steam
- The heating output reduces slightly
- The fan stops temporarily
This is normal and lasts only 5–15 minutes.
Check and Clear the Outdoor Unit
After heavy snow, check that the outdoor unit is not buried or blocked. Clear any snow build-up from around the unit (not on the coil itself). Ensure water draining from the unit during defrost has somewhere to flow — a frozen condensate drain can cause problems.
Maintain a Steady Temperature
Rather than a large temperature setback overnight, consider reducing your target temperature by just 1–2°C. The energy required to reheat a cold house from scratch is often more than the savings from a bigger setback.
Book Your Annual Service Before Winter
The best time for an annual heat pump service is autumn, before the heating season begins. This ensures your system is running at peak efficiency before you need it most and catches any faults before they leave you without heat in January.
Sources: Electrification of Heat project and heat pump tariffs.
