04/2011 - Art. Nr. 4200 1037 0000A
34
Maintenance
Troubleshooting
Fault diagnosis and repair
Faults
In the event of a malfunction, first check
that the prerequisites for correct
operation are fulfilled:
1.
Is the system connected to the
power supply?
2.
Is there any gas pressure?
3.
Is the gas shut-off valve open?
4.
Are all control and safety devices,
such as the boiler thermostat, low
water level detector, limit switch,
etc. adjusted correctly?
If the malfunction persists, use the
following table.
It is not permitted to repair any
components relevant to safety. These
components must be replaced by parts
with the same order number.
Only use original spare parts.
NB:
After each operation:
• Under normal operating conditions
(doors closed, hood fitted, etc.), check
combustion and check the individual
lines for leaks.
• Record the results in the relevant
documents.
Symbol
Symbol Fault
Cause
Remedy
No heat request
Thermostats defective or incorrectly adjusted
Adjust the thermostats, replace if
necessary.
Burner does not start after
thermostat shutdown.
No malfunction indicated on the
automatic combustion control unit.
Drop in supply voltage or power failure.
Control unit malfunction.
Check the cause of the fall in voltage or
the power failure.
Replace the control unit.
Burner starts briefly when switched
on, switches off and the red LED
lights up.
Control unit was deliberately shut down.
Unlock the unit.
Burner does not start.
Air pressure switch: not in rest position
Incorrect adjustment
contact is welded
Readjust the pressure switch.
Replace the pressure switch.
Burner does not start.
Normal gas pressure
Insufficient gas pressure
Gas pressostat wrongly set or defective
Check gas lines.
Clean the filter.
Check the gas pressostat or replace the
compact gas unit.
Burner blower starts up. Burner
does not start.
Air pressure switch: the contact does not close Check the pressure transmitter (foreign
bodies) and wiring.
Burner blower starts up. Burner
does not start.
Flaring during pre-ventilation or pre-ignition.
Check the valve. Check flame
monitoring.
The burner starts, the ignition
switches on, then failure
No flame at the end of the safety period.
Gas throughput set incorrectly.
Faulty flame monitoring circuit
No ignition arc.
Electrode(s) short-circuited.
Ignition cable damaged or defective.
Ignition transformer defective
Automatic combustion control unit.
Solenoid valves do not open.
Valves jamming.
Adjust the gas throughput.
Check the condition and position of the
ionisation sensor in relation to earth.
Check the condition and connections of
the ionisation circuit (cable(s) and
measurement bridges).
Adjust, clean or replace electrode(s).
Connect or replace the cable(s).
Replace the transformer.
Replace the control unit.
Check the cabling between the control
unit and external components.
Replace the compact gas unit.
Replace the valves.
The burner switches off during
operation.
Air pressure switch: contact opens during start-
up or during operation.
Flame failure during operation.
Adjust or replace the pressure switch.
Check the ionisation sensor circuit.
Check or replace the automatic
combustion control unit.
