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15. FAULT LOCATION GUIDE
15.1 Gas burner
The basis for a trouble free operation can only be ensured by the
correct combined effect of the three factors:
electricity, gas flow and combustion air. Should any of these factors
change, troubles may arise.
It has been proved that many troubles have rather simple causes.
Before calling the serviceman, the following checks should be made:
1. Are the gas cocks of the installation open?
2. Are the fuses in order and the current switched on?
3. Are the controls (room thermostat, boiler thermostat
etc.) correctly adjusted?
4. Is the gas pressure to the burner sufficient?
5. Is the gas relay of the burner ready for start and not locked out?
6. Is the air supply to the burner sufficient?
To facilitate fault location we have drawn up a scheme showing the
most frequent faults in a gas burner installation and the remedies.
Cause
Remedy
The burner does not start
No gas
Check that all gas cocks are open
No voltage
Check fuses, thermostats and
electrical connections.
The burner motor fails to start
The thermal protection has
locked out. Motor defective
The gas relay is defective
Replace
Burner motor is running but no
ignition after the pre-purge time has elapsed
No voltage on the terminals
Check the contact. Replace faulty
relay
The ignition electrodes in contact
with each other or with earth
Adjust
The porcelain of the electrodes is
broken
Replace the electrodes
The cable shoes have bad contact Improve the contact
The ignition cables are damaged Replace
The ignition transformer is dam-
aged, no voltage on the second-
ary side
Replace the transformer
The ignition cable and the ionisa-
tion cable have been transposed
Change