Cause
Troubleshooting
Remedy
5. Shut-off main tap in heating sys-
tem.
Check that the main tap is open.
Open closed main tap.
6. Cable break or loose cable to high
pressure switch.
•
Check that both cables are connected
to the pressure switch.
•
Using the buzzer, check that there are
no cable breaks. In order to do this,
disconnect the cables from the pres-
sure switch and circuit board.
If a cable has come loose, reconnect it.
If there is a cable break, replace the
cable.
7. The high pressure switch does not
open.
•
Incorrect pressure switch installed.
Same or higher break pressure than
the high pressure switch. See mark-
ing.
•
Pressure switch fault, opens at a
higher pressure than indicated (mark
pressure). Check using the manome-
ter apparatus.
•
Defective pressure switch, never
opens.
If the high pressure switch does not
open, replace it.
8. The high pressure switch opens too
soon.
•
Incorrect pressure switch installed. As
low or lower break pressure than
operating pressure switch. See mark-
ing.
•
Pressure switch fault, opens at a lower
pressure than indicated (mark pres-
sure). Check using the manometer
apparatus.
•
Defective pressure switch, always
open.
If the high pressure switch opens too
soon or is always open, replace it.
9. External system shunt that closes
on time setting.
Check for shunts or valves in the system,
which are timer-controlled, that close
down the entire or too large a part of the
heating system.
Always ensure that there is a sufficiently
large water volume for the heat pump to
work against, i.e. for the heat to give off
its heat to.
10. Incorrectly facing non-return valve
with too high opening pressure.
•
Check the system’s direction of flow
and that the non-return valve is
turned the correct way.
•
Check that the heat pump’s external
available pressure exceeds the non-
return valve’s opening pressure.
If the non-return valve is facing the
wrong way, turn it.
If the non-return valve has too great an
opening pressure, replace it.
11. Large pressure drop in the heating
system.
•
Dirt in the heating system.
•
Closed or partially closed thermo-
stats/valves in the heating system.
•
Under dimensioned pipe system.
Check that the HP’s external available
pressure exceeds the system pressure
drop.
If necessary, clean/flush the heating sys-
tem.
Open closed thermostats/valves.
If there is not sufficient pressure equip-
ment, the heating system can be adjus-
ted according to the system solution for
large pressure drop.
16 – Service instructions VMGFJ102
