Installation and operating instruction
Oil condensing boiler WTC-OB 18-B
10 Troubleshooting
83311002 1/2018-03 La
96-132
The following faults must only be rectified by qualified personnel:
Warning codes Cause
Rectification
W88
Communication to EM#8 or WCM-FS#8 is
faulty
Check address
Check the connection
Replace the extension module
Replace remote control station
W89
Temperature remote control is faulty
Test the setpoint signal [ch. 6.6]
Check the connection
10.4 Fault codes
The following faults must only be rectified by qualified personnel:
Fault codes
Cause
Rectification
F11
Temperature at supply sensor > 105 °C
Check the water flow
Check function of the pumps
Vent unit on the water side
F12
Temperature at supply sensor > 95 °C
Check the water flow
Check function of the pumps
Vent unit on the water side
F13
Flue gas temperature is too high
(see parameter
33
)
Check heat cell
F15
Temperature differential between flow and return
too high
(see also
W15
)
Check function of pump, if necessary increase
pump capacity
Ensure system circulation
F16
Flue gas temperature too high
(see also
W16
) (parameter
33
- 5 K)
Wait for cooling (10 minutes)
Check heat cell
F17
Combustion air temperature too high
Wait for cooling (10 minutes)
Check the heat insulation
Check combustion air sensor, replace if ne-
cessary
Flow sensor and combustion air sensor mixed
up, check electrical connections
F19
Combustion chamber pressure too high
(see also
W19
)
Check heat cell, if necessary clean [ch. 9.5]
Check flue gas system
Check the condensate drain
Check combustion chamber pressure sensor,
if necessary replace
Check combustion for pulsation, if necessary
increase mixing pressure
F21
No flame formation at burner start
Check oil nozzle, if necessary replace
[ch. 9.10]
Check oil supply
Check oil pump, if necessary replace
[ch. 9.14]
Check the ignition unit and replace if neces-
sary
Check flame sensor (USB-readout unit
KLC Com, Order No.: 90012181), if neces-
sary replace
Clean the light tube end piece, if necessary
check burner setting.
Check solenoid valve, if necessary replace
Check burner setting
Set nozzle distance [ch. 9.6]
Check mixing head [ch. 9.7]