Danfoss DHP-A Service Instructions Manual page 26

Service instructions
2.4.6 Other
Problem – The heat pump runs and runs but never stops
Cause
1. Air in the heating system.
2. Lack of refrigerant, not enough
refrigerant in the system.
3. Changed conditions Have you in-
creased your heating and/or hot
water demand?
Problem – Runs on electric heating element
Cause
1. Operating mode AUX. HEATER is
selected.
2. The compressor cannot run due
to an alarm.
3. The integral value has reached
the start level for the auxiliary heat-
er.
4. Peak heat operation (anti-legion-
ella function) is running.
26
Domestic heat pumps
Troubleshooting
Listen for air in the heat pump and heating system. Bleed the heating system according to the
Using manometer apparatus and thermometer,
check that the unit's overheating is correct for the
specific refrigerant.
▪ If the heat pump has been dimensioned for a
certain demand and this demand is increased,
the heat pump might not be able to maintain
the desired room temperature.
▪ If hot water consumption increases, a larger
proportion of time is used to produce hot wa-
ter, which means less time for heat produc-
tion.
Troubleshooting
If this operating mode is selected, the auxiliary
heater is used for heating and hot water produc-
tion, not the compressor.
Check the alarm that is indicated in the display.
Check what the integral value is in the control sys-
tem.
Check if the heat pump runs peak heat. See the in-
structions for the relevant model.
VIGFI102
Remedy
installation instructions.
Follow the correct procedure (depending
on type of refrigerant) to add the correct
amount of refrigerant.
If there appears to be a leak in the refriger-
ant circuit, carry out leak tracing and any
necessary corrective action. If leak tracer is
not available, brush soap water on the sus-
pected leak and look for bubbles. Also
check for oil as this can come out from the
refrigerant circuit.
If the heat pump cannot cope with the de-
mand, replace it with one with a higher
output or supplement it with a higher out-
put auxiliary heater.
Remedy
If AUX. HEATER mode is selected and you
no longer want it, change to AUTO, the
heat pump then controls both the com-
pressor and auxiliary heater.
Rectify the problem and rest the alarm. See
chapter Alarm.
If the auxiliary heater is in operation be-
cause the integral value has counted down
to the start value, the computer reacts as it
should, see chapter Important parameters
for more information.
Peak heat operation occurs in connection
with hot water production with the set in-
terval. The compressor should then start to
produce hot water and 2 minutes later the
auxiliary heater starts. The compressor
must then stop and the stop temperature
be reached with only the auxiliary heater
connected. Take no corrective action.
Danfoss Heating Solutions