Fault Diagnosis And Correction - Viessmann VITODENS 100-W Operating Instructions & User's Information Manual

Operation

Fault Diagnosis and Correction

Issue
Heating system does not start up
Burner does not switch on or
only intermittently
Burner does not start up; burner
fault, "U" is displayed on control
unit
Burner does not start up, no fault
"U" display. "r" and / or "w"
on the display
Burner does not start up; burner
fault "U" appears in display
The burner switches off even
though the desired room
temperature has not been
reached
Rooms are cold although burner
is operating
Rooms are not at the required
temperature, even though the
temperature is operating
DHW temperature is too low
Fault code "58" appears on the
display
14
Cause
Heating system switch turned to
OFF on control unit
Selector dial "tr" is set to "0".
Circuit breaker or fuse in power
supply or in boiler control unit has
blown or tripped
No gas
Fault on control unit
Faulty start-up
Fault on control unit
No water flow
Power supply too low
Fault in combustion air supply or in
the venting system
Heating water temperature or room
temperature is set too low
Air in heating system
Domestic hot water supply has
priority (operation with DHW storage
tank only)
Fault on programmable room
thermostat
Circulation pump fault
DHW priority
Circulation pump faulty
DHW temperature is set too low or
rotary selector " " is set to "0"
(only with the CombiPLUS kit)
Jumper connection shorted out,
removed or missing
Vitodens 100-W, WB1B Operating & User's Information
Corrective Action
Turn switch to ON on control unit.
Set required heating water temperature
(see page 10).
Inform heating contractor.
Open gas shut-off valve or contact your
gas supply company.
Make a note of the fault code and inform
heating contractor.
Press ON / OFF switch to OFF position and
then back ON. This will reset the boiler
fault (see page 10). Should this attempt
fail, contact your heating contractor.
Flow switch defective or boiler pump
failure. Inform heating contractor.
Contact your Hydro company.
Contact your heating contractor.
Increase heating water temperature by
turning selector dial "tr" or by increasing
desired room temperature on the room
thermostat.
Wait until the domestic hot water heating
is complete.
Contact your heating contractor.
Contact your heating contractor.