Daikin Rotex GW-20 C28 Installation Instructions Manual page 49

8.3.8 CH installation stays warm unwanted
Possible causes:
Room thermostat/weather dependent regulation
faulty or short circuited.
No 
CH installation is heated due to Tap comfort.
The service display regularly shows code 7.
8.3.9 A-label pump LED flashes intermittently red/green
Possible causes:
Too high or too low mains voltage.
No 
Pump temperature is too high.
8.3.10 A-label pump LED flashes red
Possible causes:
Pump stopped.
ROTEX Heating Systems GmbH
Solution/cause:
Check the wiring.
Check OpenTherm and On/off connection of the unit.
Yes 
Replace the thermostat.
Replace the weather-dependent regulation.
Unwanted circulation in the CH circuit due to thermosiphon effect or second pump in
Yes  the CH circuit. Install a check valve in case of thermosiphon effect or a two-way
valve in case of a second pump.
Solution:
Yes  Check the mains voltage.
Yes  Check the water and ambient temperature.
Solution:
Reset the pump by switching off the unit by pressing the on/off button for at least 20
seconds (attention: if the pump has been set to continuous, the pump can only
Yes 
be reset by pulling the plug from the socket).
Replace the pump.
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