Viessmann Vitocrossal 200 Service Instructions For Contractors page 49

Fault codes
(cont.)
Displayed System characteris-
fault code tics
F 83 Burner control unit in
a fault state
F 88 Burner control unit in
a fault state
F 89 Burner control unit in
a fault state
F b7 Burner control unit in
a fault state; system
cools down; burner
control unit locked
out
F b7 Type of coding card
F E1 Burner control unit in
a fault state
F E2 Burner control unit in
a fault state
Cause
Sensor drift, flue
gas temperature
sensor (A or B),
burner control unit
Lead break, boiler
water temperature
sensor, burner
control unit
Lead break, flue
gas temperature
sensor (A or B),
burner control unit
Coding card not in-
serted in the burner
control unit; incor-
rect or faulty cod-
ing card
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
Troubleshooting
Measures
Check lead and sensors
(A and B), replace sensor
if required
Check lead and dual sen-
sor; replace sensor if re-
quired
Check lead and sensors
(A and B), replace sensor
if required
Insert coding card; check
coding card; replace if re-
quired
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
49