Glow-worm Clearly Heat Pump 5 kW - Manual (Page 24)

0020111744_00 - 09/10 - Glow-worm
- 22 -
MAINTENANCE
Fault
codes
Description Cause Solution
537
The compressor discharge
pressure is too high
(> 42 bars).
Blocking failure
There is an excess or a lack of
refrigerant.
Measure the air and water’s ΔT. If it is very low (<2K), lack of fl uid
may be the cause (loss of heat output). Measure the real overheating
(must be <7K in heating mode). Measure the electrical current with an
ammeter. If the current is below 4.5 amps, the cause may be a lack of
fl uid.
Check the pressure with a monometer.
Check that there are no leaks, repair them if necessary.
Adjust the amount of refrigerant.
The pressure switch is defective.
Check the pressure with a monometer, change the pressure switch.
Check that there are no leaks, repair them if necessary.
The pressure switch contact is
insuffi cient.
Check the resistance of the switch.
The cables are defective. Check the condition of the switch cables.
Pre-expansion in the liquid line
(load loss) Check the appearance of the condenser output tubes leading to the
evaporator (do not pinch).
The water fl ow sensor is
defective. Check absence of water fl ow by forcing the pump. Consult the
"Adjusting the HP fl ow circuit” chapter.
The electronic expansion valve is
defective.
Check that the motor is correctly clipped to the regulator.
Check that the electronic is working correctly, if this is not the case:
Check the winding resistance.
Replace the motor.
Replace the electronic expansion valve, check that there are no leaks.
Insuffi cient heat exchange at the
plate to plate exchanger.
Clean the heat exchanger plates.
The heating outlet and return
temperature sensors are
defective Check the sensor connections.
Check that the sensor position and operation are correct.
Check the sensor resistance.
The air temperature is too high in
cooling mode
Check the agreement between the outside sensor and heat pump air
inlet temperature sensor.
Check that the heat pump air inlet temperature sensor is working
properly.
In de-icing mode, the de-icing
sensor is defective or misplaced.
Check the sensor connections.
Check that the sensor position and operation are correct.
Check the sensor resistance.
539
The pressure of the low
pressure circuit is too low in
heating mode (> 4.5 bars).
Blocking failure if produced
more than 4 times.
Lack of refrigerant.
Measure the air and water’s ΔT. If it is very low (<2K), lack of fl uid
may be the cause (loss of heat output). Measure the real overheating
(must be <7K in heating mode). Measure the electrical current with an
ammeter. If the current is below 4.5 amps, the cause may be a lack of
fl uid.
Check the pressure with a monometer.
Check that there are no leaks, repair them if necessary.
Adjust the amount of refrigerant.
Lack of airfl ow.
Check that no obstacles are blocking the air input and output.
Check the condition of the fan blades.
There is no defrosting.
Check that the 4-way valve is not blocked (switch the heat pump ON /
OFF). Force in the defrost mode and check the reverse cycle.
Check the position of air exchanger air intake temperature sensor.
Check the position and proper operation of the de-icing sensor.
The condensate tray resistance
heater is faulty. Measure the condensate tray resistance heater.
Change the resistance.
The electronic expansion
valve’s motor is defective or the
connection is defective.
Check that the electronic expansion valve is working correctly, if this is
not the case:
Check the winding resistance.
Clip the electronic expansion valve back on.
Replace the motor.
Replace the electronic expansion valve, check that there are no leaks.
The heating outlet and return
temperature sensors are
defective. Check the sensor connections
Check that the sensor position and operation are correct.
Check the sensor resistance.
The compressor casing
resistance heater is defective.
Check the compressor’s electric resistance power supply.