Daikin EKOMB22AAV1H Installation Instructions Manual page 50

Insufficient heat transfer due to lime scale or
contamination in the CH boiler on the tap water
side.
9.3.8 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.
9.3.9 A-label pump LED flashes intermittently red/green
Possible causes:
Too high or too low mains voltage.
No 
Pump temperature is too high.
9.3.10 A-label pump LED flashes red
Possible causes:
Pump stopped.
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Yes  Remove lime scale or rinse the CH boiler on the tap water side.
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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