Specifications

7 181 465 346 GB (03.02)
42
Failure identification procedure
3.4 Faults that are not displayed
3.4.1 Appliance faults
Excessive burner noise, rumbling noises
Check Action
B Note the setting of the temperature controls
and .
1. Does the gas supply type match the
specifications on the appliance iden-
tification plate?
yes: ↓2.
no: B Convert appliance to correct gas type.
↓2.
2. B Test gas supply pressure - OK?
Does pressure match figure speci-
fied in installation instructions?
yes: ↓3.
no: B Decommission appliance.
For natural gas:
B Notify gas company.
3. Problem with flue?
B Check CO
2
level in combustion
air.
Is CO
2
level above 0,2 % ?
yes: B Check flue and repair or replace if necessary.
no: ↓3.
4. Cascade system:
Is the appliance min. output high
enough to open the shut-off device?
yes: ↓5.
no:
B Press buttons and simultaneously.
B Select Service Function 5.5 .
B Increase min. output.
5. Is appliance’s internal air/flue chan-
nel leaking or blocked?
B Open up heat exchanger and
inspect.
B Remove silencer, flue duct and air
flow limit.
B Open trap and inspect.
Air channels dirty/clogged, seals
defective or not correctly fitted?
yes: B Repair or replace components.
B Grease seal before fitting.
B Make sure it is fitted in correct position.
no: ↓6.
6. B Measure CO
2
levels.
CO
2
levels in flue gas at min and
max output do not match figures
specified in installation instruc-
tions.
yes: B Adjust CO
2
level as per installation instructions.
no: B Turn off gas cock.
B Power OFF the appliance.
B Change the gas valve.
B Open the gas cock.
B Turn ON the appliance.
B Check appliance for leaks.