Troubleshooting; Analog Burner Control Unit - Buderus Logano GE434 Maintenance Instructions Manual

Troubleshooting

11 Troubleshooting

11.1 Analog burner control unit

Fault
The burner does not
start.
Burner starts and
enters fault state.
No ignition spark
recognised.
Burner starts and
enters fault state.
No pilot flame
recognised.
Burner starts and
enters fault state.
Only a very small pilot
flame is recognisable.
Burner starts and
enters fault state.
A perfect pilot flame is
recognisable.
No ionisation current
can be measured.
Burner starts and
enters fault state.
A perfect pilot flame is
recognisable.
Ionisation current
< 1.5 µA.
Boiling noises
We reserve the right to make any changes due to technical modifications.
Commissioning and maintenance instructions Logano GE434 Gas-fired special boiler • Issue 02/2003
Possible causes for faults
Heating system emergency stop switch ON?
Control device ON/OFF switch ON?
Fuses OK?
Boiler water thermostat is satisfied?
High limit safety cut-out has tripped?
Fault signals from external safety equipment
(e. g. low water indicator)?
Ignition spark audible with ignition cable pulled
off?
Are all gas shut-off valves open?
Natural gas supply pressure > 10 mbar?
Gas supply pipe purged?
Burner warm – pilot flame OK and cold burner –
no pilot flame?
Pilot burner nozzle contaminated?
Can you hear the pilot gas valve's opening click? If not: Check wiring and plug contacts.
Pilot burner nozzle contaminated?
Natural gas supply pressure > 10 mbar?
N and L leads interchanged?
Voltage between L and PE?
No proper ionisation lead contact?
Earth connection at ionisation electrode?
Burner control unit faulty?
Ionisation electrode wire or ceramics
contaminated?
Scale deposits or boiler scaling?
Remedy
Switch ON
Switch ON
Check continuity and replace fuse, if required.
Check and replace faulty parts, if required.
Check and replace faulty parts, if required.
Check the on-site installation of the heating system
and correct faults; if required replace faulty devices.
If not: Replace the ignition transformer.
If yes: Replace ignition electrode or pilot burner,
if required.
Open all gas shut-off valves.
If not: Check cause and remedy fault.
Purge until gas is flammable.
If yes: Replace the ignition transformer.
Blow out pilot gas pipe and nozzle.
Blow out pilot gas pipe and nozzle.
If not: Check cause and remedy fault.
Remedy the fault.
If not: Earth PE and install isolating transformer, if
required.
Remedy fault and replace faulty part, if required.
Clean ionisation electrode and replace start-up
burner, if required.
Clean the boiler waterways in accordance with
manufacturer's details. Check and remedy the cause
of constant water losses. If required, treat the water
and install a dirt trap.
Buderus Heiztechnik GmbH • http://www.heiztechnik.buderus.de
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