Viessmann MatriX Service Instructions For Contractors page 36

Troubleshooting
Fault codes
(cont.)
Displayed fault System characteristics
code
F 82 Burner control unit in a fault
state; system cooling down;
burner control unit locked out.
F 83 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 cooling 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
F E2 Shortage of gas to gas pres-
sure 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
F EF Burner control unit in a fault
state
36
Cause
Short circuit, flue gas tem-
perature sensor (A or B),
burner control unit
Sensor drift, flue gas tem-
perature sensor ( A or
aG
B), burner control unit
Lead break, flue gas tem-
perature sensor ( A or
aG
B), burner control unit
Coding card not inserted
in the burner control unit;
incorrect or faulty coding
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.
Gas valve does not open;
gas valve leaking; gas
pressure switch 2 faulty.
Multiple detection of un-
dervoltage with recurrence
and renewed undervolt-
age
Internal fault of the burner
control unit and during test
of ionisation input
Internal fault in feedback
from gas safety valves;
output relay does not re-
spond.
Internal fault in feedback
from gas safety valves;
output relay does not re-
spond.
Measures
Check connecting cable and sen-
sors (A and B); replace sensor if
necessary.
Check connecting cable and sen-
sors ( A and B); replace sensor if
aG
necessary.
Check connecting cable and sen-
sors ( A and B); replace sensor if
aG
necessary.
Insert coding card; check coding
card and replace if necessary.
Replace coding card or burner
control unit.
I
Danger
Plug-in terminals on the burn-
er control unit are live.
Only replace the coding card
when the burner control unit
has been isolated from the
power supply.
Check setting of gas pressure
switch 2; check connecting cable;
replace gas train.
Check setting of gas pressure
switch 2; check connecting cable;
replace gas train.
Replace gas train.
Check the power supply.
Replace burner control unit.
Reset burner control unit; replace
burner control unit.
Reset burner control unit; replace
burner control unit.