Diagnosis - Viessmann WB1A Series Installation And Service Instructions Manual

Diagnosis

(continued)
Diagnostics table: Faults with fault display on control unit
Fault mes- System behavior
sage in dis-
play window
0b
Burner blocked
0c
Burner blocked
30
Burner blocked
38
Burner blocked
b1
Control mode
b5
Control mode
e4
Burner blocked
e5
Burner blocked
e6
Burner blocked
f0
Burner blocked
f2
Burner in fault mode
f3
Burner in fault mode
f4
Burner in fault mode
f5
Burner blocked
All manuals and user guides at all-guides.com
9
tr
Cause
Insufficient water flow.
Incorrect flow direction.
Defective flow switch.
Insufficient power supply
Boiler temperature sensor shorted
out
Boiler temperature sensor lead break Check the boiler temperature sensor
Communication fault - internal pro-
gramming unit
Internal fault
Fault with the supply voltage (power
pump module)
Internal fault
Water pressure too low
Internal fault
Fixed high limit tripped
The flame signal is already present at
burner start
No flame signal is present
Faulty air pressure switch
Troubleshooting
Faults are indicated by a flashing fault
code with fault code sysmbol "
the reset button is illuminated.
For fault code explanations see the
following table.
Corrective measures
Check proper heating circuit pump
size and operation.
Check flow direction.
Check flow switch connection cable.
Contact your local hydro company.
Check the boiler temperature sensor
(see page 65).
(see page 65).
Check connections and replace the
control unit if necessary.
Replace control unit.
Check connections. Replace control
unit.
Check ignition and ionization elec-
trodes and leads.
Press "Reset".
Top up water .
Replace control unit.
Check the heating system water
level. Check the circulation pump
operation. Vent the heating system
of air. Check the fixed high limit and
leads.
Press "Reset".
Check the ionization electrode and
leads.
Press "Reset".
Check the ionization electrode and
leads, check the gas pressure, check
the gas combination valve, control
unit and condensate drain see page
56).
Press "Reset".
Check the air pressure switch and
the interconnecting cable.
Check the burner air/gas
mixture damper. Reference the
Burner Damper Replacement
Instructions.
" and
U
63