elco VG 1.105 D E - Troubleshooting; Fault diagnosis and repair; Malfunction table

09/2018 - Art. Nr. 4200 1092 1400A 31
en
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.

Malfunction Cause Remedy
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 does not start.
Gas pressure normal
Air pressure switch OK
No heat request
Insufficient gas pressure
Gas pressure switch wrongly set or defective
Air pressure switch not in rest position
Thermostats defective or incorrectly adjusted
Check gas lines.
Clean the filter.
Check the gas pressure switch or replace the
compact gas unit.
Adjust the air pressure switch, replace if
necessary.
Adjust the thermostats, replace if necessary.
Burner starts briefly when switched on,
switches off and outputs the following signal:
-
Control unit was deliberately shut down. Unlock the control unit.
Burner does not start.

Air pressure switch: not in rest position
Incorrect adjustment
Contact welded
Readjust the pressure switch.
Replace the pressure switch.
Burner blower starts up. Burner does not start.

Air pressure switch: 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 after the safety time.
Gas throughput set incorrectly.
Malfunction in flame monitoring system
No ignition sparks.
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 valves.
The burner switches off during operation.

Air pressure switch: contact opens during start-
up or during operation.
Adjust or replace the pressure switch.
The burner switches off during operation.

Flame failure during operation. Check the ionisation sensor circuit.
Check or replace the automatic combustion
control unit.