Viessmann Vitodens 300 - Page 82

Displayed
fault c ode
Con-
st.
Weat -
her-
com-
p.
System
character-
istics
Cause Remedy
CF X Control
mode
Communica-
tions fault -
LON commu-
nication mod -
ule
Replace the L ON
communicati on
module
dA X Control
mode with-
out room
influenc e
Room tem-
perature sen-
sor heating
circuit A1
shorted out
Check the room
temperature sensor
for heating circuit
A1
db X Control
mode with-
out room
influenc e
Heating circuit
M2 room tem-
perature sen-
sor shorted
out
Check the room
temperature sensor
for heating circuit
M2
dd X Control
mode with-
out room
influenc e
Room tem-
perature sen-
sor heating
circuit A1 lead
break
Check the room
temperature sensor
for heating circuit
A1
dE X Control
mode with-
out room
influenc e
Heating circuit
M2 room tem-
perature sen-
sor lead break
Check the room
temperature sensor
for heating circuit
M2
E4 X X Burner
blocked
Fault - supply
voltage
Replace control unit
E5 X X Burner
blocked
Internal fault Check the ionisa-
tion electro de a nd
leads. Check flue
gas system for
soundness.
Press E.
E6 X X Burner in
fault state
Flue gas/air
supply system
blocked
Check the flue gas/
air supply system.
Check the differen -
tial pres sure sen-
sor.
Press E.
Checking and acknowledging faults (cont.)
82
Troubleshooting
5692 537 GB