Heat Pump Fault Investigation

What the investigation covers

This service is focused on identifying the cause of a fault, not guessing. Depending on your system and symptoms, the investigation can include:

• Review of reported symptoms, recent changes, and any error codes or lockouts
• Visual checks for leaks, corrosion, blockages, damaged insulation, or signs of overheating
• Tests of system pressures, flow and return temperatures, and basic operational performance
• Checks of filters, strainers, pumps, valves, expansion vessel, and safety devices (where fitted)
• Controls and wiring checks for thermostats, programmer, sensors, and communications issues
• Assessment of heating distribution issues that can mimic heat pump faults (radiators, UFH manifolds, air locks, balancing)
• Hot water cylinder and immersion heater checks where hot water performance is affected
• Clear findings and recommendations, with repair options prioritised by impact and urgency

When this service is the right fit

Book a fault investigation if your heat pump is short cycling, struggling to reach temperature, making unusual noises, frequently defrosting, or showing repeated error codes. It is also suitable when running costs have risen and you need to confirm whether the issue is the heat pump, the controls, or the heating system it serves. Landlords and small commercial sites often use this service to get a documented diagnosis before authorising repairs.

What happens during the visit

The visit starts with a few questions about the fault history and your current settings, followed by a structured inspection and targeted testing. Readings are taken to confirm what the system is doing in real conditions, then the most likely causes are narrowed down and explained in plain terms. If a straightforward issue is found and it is safe to do so, minor adjustments may be made as part of fault-finding, but the main purpose is accurate diagnosis.

After the investigation

You will receive a clear summary of what was checked, what was found, and what needs to happen next. Where a repair is required, you will be advised on the best remedial action, any parts likely needed, and whether the issue sits within the heat pump unit, the controls, or the wider heating system. If specialist work is required (for example, refrigerant circuit repairs), this will be flagged and the options explained.