Troubleshooting guide
7
VMIFB202
Troubleshooting Guide Alarm high pressure
The operating pressure switch does not open but the heat pump opens at high pressure
Action:
Check that the operating pressure switch opens at the correct pressure, using manometer apparatus.
If the high pressure switch opens at a lower pressure than indicated there is a fault in the high pressure switch
If the high pressure switch opens at the incorrect pressure, replace it.
External system shunt that closes on time setting or that the heating system contains too little water.
Action:
Check for timer-controlled shunts or valves in the system that close down the entire or too large a part of the heating system.
Ensure that there is a suciently large water volume for the heat pump to work against, i.e. for the heat pump to give o its heat to. (
approx ). 14-15 litres/kw heat pump) at smaller volumes there is a lot of starting and stopping and a risk of the high pressure alarm
deploying.
Incorrectly facing non-return valve with too high opening pressure
Action:
Check that the non-return valve is in the correct direction of ow.
Check that the heat pump’s external available pressure exceeds the non-return valve’s opening pressure.
Large pressure drop in the heating system
Action:
Check the system for closed taps or valves inside or out of the heat pump.
Check for dirt in the heating system.
Check that the heat pump’s external available pressure exceeds the heating system’s pressure drop.
Check if the heating system is under dimensioned