Air Source Units
Air Source Heat Pumps Troubleshooting
HP / LP Alarm: Commonly referring to an issue with flow; high pressure / low pressure
HP Alarms, in general, indicate a flow issue leaving the heat pump to either the hot water or the heating system. In other words; a restriction of some sort, preventing the intended flow / return, to and from the heat pump.
LP Alarms frequently indicate a flow issue coming into the heat pump. If the fan is still operating as usual, it’s highly likely that there is an issue with the refrigeration circuit. However, a faulty pump or faulty valve could not be ruled out.
The initial areas for investigation would be to check whether there is:
– blocked filter
– faulty pump
– faulty valve
– glycol leak
– refrigerant circuit issue
Only a suitably qualified F GAS engineer can fully investigate refrigerant issues due to the safety requirements in handling gasses.
In some instances, flow can be restricted due to systems requiring a power flush. Over time, debris can build up within radiators and connecting pipework causing ‘blockages’ that affect flow. A chemical flush may aid to dislodge debris and improve this.
MP Alarm: Refers to an electrical issue, whereby the internal protection system has tripped
MP alarms indicate the heat pumps electrical protection device has tripped to protect other vital components.
This can happen frequently when properties are located remotely, with an inconsistent electrical supply, or otherwise during an electrical storm. These alarms can normally be reset with remote assistance but a visit to site could be required. In the event the alarm cannot be reset or occurs frequently, it is likely that a component has failed, and further investigation would be required.
Each manufacturer will likely have a set of unique fault codes or references inbuilt to the system that may provide specific information or location of error for investigation. For further information, please refer to the relevant link below:
