Viessmann MatriX, Service Instructions Manual

Page: 31 / 48

31
Fault code System characteris-
tics
Cause Measures
26 Ionisation flame mon-
itor reports external
light ingress during
start-up or after post-
purge Gas train leaks Replace gas train
26 Ionisation flame mon-
itor reports external
light ingress during
start-up or after post-
purge Incorrect parame-
ter set selected Adjust the parameter set
(see page 24 to 25)
27 Flame extinguishes
during operation Incorrect gas type
selected Adjust the gas type (see
page 7)
27 Flame extinguishes
during operation Burner gauze
assembly faulty Replace burner gauze
assembly
27 Flame extinguishes
during operation Incorrect parame-
ter set selected Adjust the parameter set
(see page 24).
27 Flame extinguishes
during operation Combustion char-
acteristics not
ideal Adjust burner (see from
page 12).
29 Burner control unit
fault Internal fault of gas
pressure switch
input Replace burner control
unit
2A Burner control unit
fault Internal fault of air
pressure switch
input Replace burner control
unit
2b Burner control unit
fault Internal flame
monitor fault Replace burner control
unit
2C Burner control unit
fault Fault during test of
safety inputs Replace burner control
unit
2d Burner control unit
fault Internal low volt-
age monitor fault Replace burner control
unit
2E Burner control unit
fault Internal voltage
failure monitor
fault Replace burner control
unit
2F Burner control unit
fault Internal heat
demand fault Replace burner control
unit
2H Burner control unit
fault Lead break, strap-
ping plug
fJ ,
safety chain
Check strapping plug
fJ
Troubleshooting
Diagnosis
(cont.)
5692 488 GB