Why Annual Servicing Matters
Annual servicing is the single most important maintenance task for a heat pump. It maintains efficiency, extends system life, keeps your warranty valid, and catches developing faults before they become expensive repairs. A well-serviced heat pump can maintain its original CoP for 15–20 years.
Outdoor Unit Checks
- Visual inspection for physical damage, corrosion, or weathering
- Clean or flush the evaporator coil (removing dirt, leaves, and debris)
- Check fan blades for damage or wear
- Test fan motor speed and current draw
- Inspect refrigerant pipework and insulation for damage
- Check anti-vibration mounts and fixings
- Test defrost sensor and control operation
Refrigerant Circuit Checks
- Check refrigerant pressures (suction and discharge)
- Calculate superheat and subcooling
- Inspect all connections for signs of refrigerant leak
- Check compressor operation and current draw
- Inspect expansion valve operation
Indoor Unit / Hydrobox Checks
- Inspect and clean air filters (if applicable)
- Check heat exchanger for scaling
- Verify flow and return temperatures
- Check system pressure and top up if required
- Inspect pump operation
- Check and test all sensors
Controls & Electrical
- Check all electrical connections for tightness and corrosion
- Test safety devices (high-pressure cut-out, low-pressure cut-out)
- Verify controller settings and update firmware if applicable
- Test weather compensation curve settings
Hot Water Cylinder (if applicable)
- Check cylinder temperature settings
- Verify legionella prevention cycle is set correctly
- Inspect immersion heater operation
- Check expansion vessel pressure
Sources: MCS and HSE guidance.
