Daikin ROTEX GW-20 H18 Installation Instructions Manual page 48

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:
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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