Viessmann VITODENS 200-W WB2B 105, Start-Up/Service Instructions

Page: 57 / 80

Troubleshooting
57
Diagnostics
(continued)
Fault codes
(continued)
Fault code on display System behavior
*1
Cause Corrective action
bA Mixing valve regulates to a
supply temperature of 20°C Communication fault -
accessory kit for heating
circuit with mixing valve Check accessory kit
connections and coding.
Turn on the accessory kit.
bC Control mode without remote
control Communication fault -
Vitotrol remote control,
heating circuit without
mixing valve, A1 Check connections, cable,
coding address ”A0” and
remote control DIP switches
(see page 66).
bd Control mode without remote
control Communication fault -
Vitotrol remote control,
heating circuit with mixing
valve, M2 Check connections, cable,
coding address ”A0” and
remote control DIP switches
(see page 66).
bE Control mode Vitotrol remote control
incorrectly programmed Check remote control DIP
switches (see page 66).
bF Control mode Incorrect LON communication
module Replace LON communication
module.
C2 Control mode Communication fault -
solar control unit Check connections and
coding address ”54”.
C5 Control mode, max. pump
speed
(Not used) Communication fault, variable
speed circulation pump,
heating circuit connection set Check setting of coding
address ”30” Set to “0”
30:”0”
C7 Control mode, max. pump
speed
(Not used) Communication fault-variable
speed circulation pump,heat-
ing circuit without mixing valve Check setting of coding
address ”E5”.
Cd Control mode
(Not used) Communication fault,
Vitocom 100 (KM-BUS) Check coding address ”95”
and set value to 95:0
CE Control mode Communication fault-power/
pump module KM-BUS connection
Check connections and set-
ting of coding address ”2E”.
CF Control mode Communication fault -
LON communication module Replace LON communication
module.
dA Control mode without room
influence Room temperature sensor,
heating circuit without
mixing valve (A1) shorted out Check the room temperature
sensor, heating circuit
without mixing valve (A1)
db Control mode without room
influence Room temperature sensor,
heating circuit with mixing
valve (M2) shorted out Check the room temperature
sensor, heating circuit with
mixing valve (M2).
dd Control mode without room
influence Room temperature sensor,
heating circuit without
mixing valve (A1) cable
broken Check the room temperature
sensor, heating circuit A1
and the remote control DIP
switch settings (see page 66).
dE Control mode without room
influence Room temperature sensor,
heating circuit with mixing
valve (M2) cable broken Check the room temperature
sensor, heating circuit M2
and the remote control DIP
switch settings (see page 66).
E4 Burner blocked Fault, supply voltage 24V Replace the control unit.
E5 Burner blocked Internal fault Check the ionization
electrode and cables. Check
tightness of flue gas system.
Press ”
RESET”.
5
4
4
3
2
0
7
v
1
.5