10.1.3 Blocking
Tab.46 Blocking codes
Code
Display text
Description
Solution
H.00.36
T 2nd Return Open
Second return temperature sensor is
either removed or measures a tem
perature below range
Second return temperature sensor open:
Bad connection: check the wiring and connec
tors.
Incorrectly fitted sensor: check that the sensor
has been correctly fitted.
Faulty sensor: replace the sensor.
H.00.37
T 2nd Return Closed
Second return temperature sensor is
either shorted or measures a tem
perature above range
Second return temperature sensor short-circuit
ed:
Bad connection: check the wiring and connec
tors.
Incorrectly fitted sensor: check that the sensor
has been correctly fitted.
Faulty sensor: replace the sensor.
H.01.00
Comm Error
Communication Error occured
Communication error with the security kernel:
Restart the boiler
Replace the CU-GH
H.01.06
Max Delta TH-TF
Maximum difference between heat
exchanger temperature and flow
temperature
Maximum difference between heat exchanger
and flow temperature exceeded:
No flow or insufficient flow:
Check the circulation (direction, pump,
valves).
Check the water pressure.
Check the cleanliness of the heat exchanger.
Check that the installation has been de-aired.
Check water quality according to supplier's
specifications.
Sensor error:
Check that the sensors are operating correct
ly.
Check that the sensor has been fitted proper
ly.
H.01.07
Max Delta TH-TR
Maximum difference between heat
exchanger temperature and return
temperature
Maximum difference between heat exchanger
and return temperature exceeded:
No flow or insufficient flow:
Check the circulation (direction, pump,
valves).
Check the water pressure.
Check the cleanliness of the heat exchanger.
Check that the installation has been correctly
vented to remove air.
Sensor error:
Check that the sensors are operating correct
ly.
Check that the sensor has been fitted proper
ly.
10 Troubleshooting
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