Viessmann VITOCROSSAL 200 Service Instructions Manual page 59

Fault codes
(cont.)
Displayed System characteris-
fault code tics
F b7 Type of coding card
F E1 Burner control unit in
a fault state
F E2 Burner control unit in
a fault state
F E2 Shortage of gas to
gas pressure switch
2; valve leak test
F E4 Burner shuts down
F E5 Burner control unit in
a fault state
F EE Burner control unit in
a fault state
Cause
Coding card does
not match burner
control unit
Valve 1 not tight /
gas pressure
switch 2 does not
open
Valve 2 not tight;
gas pressure
switch 2 does not
close
Gas valve does not
open; gas valve
leaking; gas pres-
sure switch 2 faul-
ty
Multiple detection
of undervoltage
with return and re-
newed undervolt-
age
Internal fault of the
burner control unit
and during test of
ionisation input
Internal error in
feedback from gas
safety valves; out-
put relay does not
respond
Troubleshooting
Measures
Replace coding card or
burner control unit
I Danger
Plug-in terminals on
the burner control
unit are 'live'.
Only replace the
coding card when
the power has been
isolated from the
burner control unit.
Check setting of gas pres-
sure switch 2; check con-
necting cable; replace gas
train
Check setting of gas pres-
sure switch 2; check con-
necting cable; replace gas
train
Replace the gas train
Check the power supply
Replace burner control
unit
Reset burner control unit;
replace burner control
unit
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