ROTEX Heating Systems GmbH
50
Check the connector X4.
Replace the faulty controller.
8.3.4
The power is reduced
Possible causes:
Solution:
At a high level of rpm, the power has decreased
by more than 5%.
Yes
Check the unit
,
siphon and output system for contamination.
Clean unit, siphon and output system.
8.3.5
CH is not reaching correct temperature
Possible causes:
Solution:
Water pressure in installation is too low
Yes
Fill up the installation.
No
Setting of room thermostat is not correct.
Yes
Check the setting and adjust if required: Set to 0.1 A.
No
Temperature is set too low.
Yes
Increase the CH temperature. See Operation CH. If there is an outdoor sensor:
Check the outdoor sensor for short circuit: rectify this.
No
Pump does not run properly. Pump setting is
too low.
Yes
Increase the pump setting or replace the pump.
No
No flow through the installation.
Yes
Check whether there is a flow through the installation: at least 2 or 3 radiators must
be open.
No
The boiler power is not set for the installation.
Yes
Adjust the power. See Setting maximum CH power.
No
No heat transfer due to contamination in the
exchanger/installation.
Yes
Rinse the exchanger/installation on the side of the CH.
8.3.6
No domestic hot water
Possible causes:
Solution:
The service display shows nothing.
Yes
Check whether the plug is in the socket.
No
The service display shows nothing.
Yes
Check the fuse, see Electrical diagram par. 10.1
No
Flow sensor does not work.
Yes
Replace the flow sensor.
No
Tap flow < 1,5 l/min.
Yes
Increase the tap flow.
No
No electricity supply on flow sensor (5V DC).
Yes
Check the wiring in accordance with the diagram.
No
S3 faulty.
Yes
Replace S3.
No
The thermostatic shower or bath tap is faulty.
Yes
The thermostatic tap only lets through cold water. This means the tap flow through
the boiler remains under 1,5. l/min. Check the thermostatic tap.
8.3.7
DHW water is not reaching the correct temperature
Possible causes:
Solution/cause:
Tap flow too high.
Yes
Reduce the tap flow. Check the dosing disk (RKOMB22AAV1 and RKOMB28AAV1)
No
CH becomes hot during tapping.
Yes
Unwanted circulation in the CH circuit due to thermosiphon effect or second pump in
the CH circuit. Install a check valve in case of thermosiphon effect or a two-way
valve in case of a second pump.
DHW water temperature set too low.
Yes
Increase the DHW water temperature, see par. 7.1.
No
Insufficient heat transfer due to lime scale or
Yes
Remove lime scale or rinse the CH boiler on the tap water side.
