Repairs - Viessmann VITODENS 100-W Installation And Service Instructions Manual

Fault messages
(cont.)
Displayed fault System characteristics
code
540 Burner in a fault state
544 Emergency function operat-
ing mode is activated for
heating circuit 2:
Mixer closes. Heating circuit
pump is operational.
545 Emergency function operat-
ing mode is activated for
heating circuit 2:
Mixer closes. Heating circuit
pump is operational.
738 Normal operation

Repairs

!
Please note
Residual water will escape when the boiler or
one of the following components is fitted or
removed:
Water-filled pipework
■
■ Heat exchanger
■ Circulation pumps
■ Plate heat exchanger
■ Components fitted in the heating water circuit
Water ingress can result in damage to other
components.
Protect the following components against
ingress of water:
■ Control unit components (in particular in the
service position)
Electrical components
■
Plug-in connections
■
■ Electrical cables/leads
Cause
Condensate backup in the
heat cell
Lead break, flow temp.
sensor, heating circuit 2
with mixer
Incorrect setting during
commissioning
Short circuit, flow temper-
ature sensor for heating
circuit 2 with mixer
OpenTherm remote con-
trol unit connected but not
configured
Troubleshooting
Measures
Check system for condensate
■
backup.
Check the condensate drain and
■
trap.
Replace insulation blocks, elec-
■
trodes and burner gauze assem-
bly if necessary.
Note
To prevent water damage, detach
fan unit before removing the burn-
er.
Reset the appliance.
Check flow temperature sensor,
mixer 2.
Measure voltage at sensor input on
electronics module. Set value:
3.3 V with sensor disconnected.
–
Check the setting in the commis-
sioning assistant. Correct if neces-
sary.
Checking setting of ADIO rotary
switch.
Check flow temperature sensor,
mixer 2.
Measure voltage at sensor input on
electronics module. Set value:
3.3 V with sensor disconnected
–
Set C.7 in the commissioning as-
sistant to a value of 14.
61