Buderus 800 - Page 46

Servicing5
Wall-mounted condensing gas boiler Buderus 800 - Subject to modifications resulting from technical improvements!
46
Code Meaning
8Y Gas fault
Possible
cause
Action
1 External switching contact (e.g. temperature-
monitoring device for underfloor heating has been
tripped or gas pressure too low
Check gas pressure detector is defective or the wires have
not been properly connected to the back of the UBA
(see subsection 5.3.18)
Code Meaning
9A System error
Possible
cause
Action
1 Regulating device may have to cope with interference – Check if for example induction fields interfere with the
regulating device
– Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
2 UBA may be defective – Press reset. If fault code remains then try to temporarily
connect a different UBA (see subsection 5.3.5)
Code Meaning
9C KIM error
Possible
cause
Action
1 Kim connected incorrectly or KIM defective Check the KIM connector and fan connector (see
subsection 5.3.21).
If the connectors are fine then contact Buderus
Code Meaning
9L Gas valve assembly error
Possible
cause
Action
1 Wiring to the gas valve incorrect, or loose wiring
connections in UBA
– Check the electrical connections of the gas valve
– Measure the resistance of the gas valve (18-55 Ohm)
– Check if for example induction fields interfere with the
regulating device
2 UBA may be defective – Press reset. If fault code remains then try to temporarily
connect a different UBA (see subsection 5.3.5)
3 Peaks in the electrical network – Check if the are any peaks in the electrical network
caused by maybe windmills or a power generator
Code Meaning
9U KIM defective
Possible
cause
Action
1 Kim connected incorrectly or KIM defective Check the KIM connector and fan connector (see
subsection 5.3.21).
If the connectors are fine then contact Buderus