GRE HPM20 Manuel D'instructions page 31

7.2 Other Malfunctions and Solutions (No display on LED wire controller)
Malfunctions
LED wire controller
no display.
Heat pump is
not running
LED wire controller
displays the actual
water temperature.
LED displays actual
Short running water temperature, no
error code displays.
Water stains on heat
Water stains
pump unit.
Observing
No power supply.
1. Water temperature is
reaching to setting value, HP
under constant temperature
status.
2. Heat pump just starts to run.
1. Fan NOT running.
2. Air ventilation is not enough.
3. Refrigerant is not enough.
1. Concreting.
2. Water leakage.
Reason
28
Solution
Check cable and circuit breaker if
it is connected.
1. Verify water temperature
setting.
2. Startup heat pump after a few
minutes.
1. Check the cable connections
between the motor and fan, if
necessary, it should be replaced.
2. Check the location of heat
pump unit and eliminate all
obstacles to make good air
ventilation.
3. Replace or repair the heat
pump unit. It must be
repaired by a professional
technician.
1. No action.
2. Check the titanium heat
exchanger carefully if it is any
defect.