Danfoss DHP-H Installation And Service Instructions Manual page 51

HP (High pressure)
Cause
Blocked condenser on
gas and/or fluid side.
Shut-off main tap on
heating system
Large pressure drop in
the heating system
(poor pipes)
Cable break / loose cable
to pressure switch
Incorrectly facing non-
return valve or too
"strong " valve = incorrect
type of valve
Supply pipe sensor fault.
Air in the heating circuit.
Blocked filter.
Operating pressure
switch incorrect break
value/does not open
Closed radiator thermo-
stats.
Circulation pump defec-
tive/jammed.
High pressure switch
incorrect break value
Overfilled refrigerant
circuit
External system shunt that
closes on time setting
Air in the refrigerant
circuit
LP (Low pressure)
Troubleshooting
Check the flow of the heating system/WH
• Are valves open (cond.)
• Check the filter
• Is the 3-way valve working? (electricity, wiring.)
• I s the circulation pump running (electricity, pump
fault, cleaning)
Air in the system
Electricity – check pressure switch (HP 31 bar (e)
(Dp 26.5 bar (e)
Wiring – Check pressure switch
Check refrigerant circuit (over heating)
Check the pressure switch's break value
Air in the refrigerant circuit.
VMBMA102
Remedy
1