Code
Display text
Description
Solution
H.02.62
Unsupported function
Zone B doesn't support the selected
function
Zone B function setting is not correct or is not al
lowed on this circuit:
Check the setting of parameter CP021.
H.02.64
Unsupported function
Zone D doesn't support the selected
function
Zone C function (DHW) setting is not correct or is
not allowed on this circuit:
Check the setting of parameter CP022.
H.02.80
Missing Cascade Ctrl
Missing Cascade controller
Cascade controller not found:
Reconnect the cascade master
Carry out an auto-detect
H.03.00
Parameter Error
Safety parameters level 2, 3, 4 are
not correct or missing
Parameter error: security kernel
Restart the boiler
Replace the CU-GH
H.03.01
CU to GVC data error
No valid data from CU to GVC re
ceived
Communication error with the CU-GH:
Restart the boiler
H.03.02
Flame loss detected
Measured ionisation current is below
limit
No flame during operation:
No ionisation current:
Vent the gas supply to remove air
Check that the gas valve is fully opened
Check the gas supply pressure
Check the operation and setting of the gas
valve unit
Check that the air supply inlet and flue gas
outlet are not blocked
Check that there is no recirculation of flue
gases
H.03.05
Internal blocking
Gas Valve Control internal blocking
occured
Security kernel error:
Restart the boiler
Replace the CU-GH
10.1.4 Locking
Tab.67 Locking codes
Code
Display text
Description
Solution
E.00.00
TFlow Open
Flow temperature sensor is either
removed or measures a temperature
below range
Flow 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.
E.00.01
TFlow Closed
Flow temperature sensor is either
shorted or measures a temperature
above range
Flow temperature sensor short circuited:
Bad connection: check the wiring and connec
tors.
Incorrectly fitted sensor: check that the sensor
has been correctly fitted.
Faulty sensor: replace the sensor.
E.00.04
TReturn Open
Return temperature sensor is either
removed or measures a temperature
below range
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
10 Troubleshooting
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