Buderus 600 - 11S Installation And Servicing Instructions page 41

Servicing
Code Meaning
6C
Ionisation message, but no flame
Possible
cause
1 There is no flame, ionisation electrode doesn't
glow, fan is turning
2 There is no flame, ionisation electrode does
glow, fan isn't turning
3 There is no flame, ionisation electrode and fan
are working
4 There is a flame, but the flame disappears
when the fan starts up
Code Meaning
6H
Flame dies out after gas valve is opened
Possible
cause
1 Gas/air ratio not in order
2 Gas supply pressure may need adjusting
3 Earthing cable may be faulty
4 Ionisation electrode may be faulty
Code Meaning
6L
Flame goes out during warm-up phase
Possible
cause
1 Gas/air ratio not in order
2
Gas supply pressure may need adjusting
3 Earthing cable may be faulty
4 Ionisation electrode may be faulty
Subject to modifications resulting from technical improvements!
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 11S/19S/24S/24C • 05/2004
Action
– Check wiring of the hot surface ignitor, measure the resistance
of the hot surface ignitor (should be between 50 and 300 Ohm).
Replace hot surface ignitor if necessary (see subsection 5.3.19
and subsection 5.3.20)
– Check the UBA's F1 fuse, replace if necessary
– Check the fan and KIM connectors and the UBA fuses
– Check and adjust the gas/air ratio (see subsection 2.1.12)
– Check for 24V – on the gas valve during start up
– Check the gas-supply pressure (see subsection 2.1.11), this
should be higher than 20 mbar for natural gas.
– Check the earthing cable connections (yellow/green wire).
– Check the cabling on the ionisation electrode
– The gas valve doesn't close properly. If there is still more than
20 V~ on the gas valve when there is no heat demand then
check the UBA by temporarily connecting a different UBA.
– Check ionisation electrode/circuit (see subsection 2.1.15 and
subsection 5.3.22)
– When both the UBA and the ionisation electrode/circuit are OK,
then replace the gas valve
– Press reset. If fault code remains than try to temporarily connect
a different UBA (see subsection 5.3.3)
Action
Check and adjust the gas/air ratio (see subsection 2.1.12)
Check the gas-supply pressure (see subsection 2.1.11),
this should be higher than 20 mbar for natural gas
Check the earthing cable connections (yellow/green wire)
Check the cabling on the ionisation electrode
Action
Check and adjust the gas/air ratio (see subsection 2.1.12)
Check the gas-supply pressure (see subsection 2.1.11),
this should be higher than 20 mbar for natural gas
Check the earthing cable connections (yellow/green wire)
Check the cabling on the ionisation electrode
Boulter Buderus Ltd. • http://www.boulter-buderus.co.uk
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