Mr West in North Devon

Water Heat Pump

Mr West in North Devon

Client: Mr West

Equipment: Domestic Air to Water Heat Pump

Fault: Hot Water Issues

HPSL were approached to investigate problems with a Grant Aerona Air to Water heat pump installed in a holiday cottage on the North Devon coast.   The property also had a solar thermal hot water installation which provided additional heat to the cylinder.


Following a visit to replace faulty parts, the system developed a problem where, despite being set to 45 degrees centigrade, the hot water would only reach 35 degrees and then drop down to around 25 very quickly.  During a thorough check of the system operation we were able to trace the fault to one of the controllers.  Field Settings on this controller were not being retained after it had powered off; this was causing the flow temperature set points to be reduced and the circulation pump being set to run continuously.  These settings were causing the system to strip heat from the cylinder.


After intensive investigation, and with constant communication with Grant UK Technical Helpdesk, the cause of the issue was found to be a faulty printed circuit board on the outdoor condensing unit combined with a temperature sensor that was reading 25 degrees above the actual temperature.  After replacing both of these parts the system was returned to its normal operation and has been stable ever since.