Danfoss DHP-H, Installation And Service Instructions Manual

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VMBMA602
Cause Troubleshooting Remedy
5. No or insufficient circulation in the heat-
ing system.
• That the strainer is not blocked.
• That no air is in the heating system. The circulation pump may have
jammed, if so, open the bleed screw and
try to release the paddle wheel using a
screwdriver for example.
Open closed valves or taps.
Check, and, if necessary, clean the
strainer.
If necessary, bleed the heating system
according to the installation instruc-
tions.
6. The submersible tube in the electric heat-
ing element is against the coils.
Check what the flow temperature is when the
overheating protection trips. It normally trips at
about 95°C.
The submersible tube can be prised out
slightly from the coils using a screw-
driver or similar. The submersible tube
must be vertical.
Problem – Alarm Brine out
Cause Troubleshooting Remedy
1. Defective sensor. Check what the sensor shows, is it a plausible/
actual value?
Measure the resistance of the sensor, check
against the ohm table in the Measurement
points section.
If the sensor is defective, replace it.
2. Brine temperature too low. Check the set value on ALARM BRINE in the
heat pump’s control computer.
The alarm is triggered when the temper-
ature on BRINE OUT is as low or lower
than the set value on ALARM BRINE. In
the factory setting this function is inac-
tive.
Problem – Alarm Brine flow low
Cause Troubleshooting Remedy
1. Incorrect system selected in the control
computer.
If the system does not contain a flow switch
but the control computer is set for the sys-
tem with flow switch, this alarm occurs.
In the menu SYSTEM, check which is selected. If the incorrect system is selected,
change it.
2. Insufficient flow. • Check whether the ground water pump is
running?
• Check the flow switch.
• Calibration/setting the flow switch.
• Blocked exchanger?
The ground water pump must start and
run together with the heat pump’s inte-
grated brine pump.
Check against the wiring diagram that
the flow switch is correctly connected.
Check that the flow switch is set for the
correct working range according to the
flow switch instructions.
If the exchanger is blocked, clean or
replace it.