74
5600 332 v1.3
Vitodens 100-W, WB1B Installation & Service
Diagnosis
Troubleshooting
Sequence of operation and potential faults during each start-up cycle
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Call for heat by control (boiler
water set-point temperature is 9º F
(5º C) above current boiler water
temperature).
Water flow switch activates plug 33.
Blower starts up.
Ignition.
Gas combination valve opens.
Ionization current builds up / flame
established (symbol
A
appears).
Burner is operating.
Increase boiler water set-point
temperature and ensure that there is
heat demand.
Check water flow switch. Replace
if necessary (min. flow 1.8 USG/m
(400 L/h).
Check boiler pump operation.
Check cabling and plug-in connectors
of the blower, as well as the blower
itself. Check proper power supply to
the blower.
Check ignition transformer unit and
its plug-in connections.
Check gas combination valve
104VRAC (DC) between brown and
blue must be present during start-up,
(plug 35). Check gas supply pressure.
Check electrode settings, purge gas
supply line. Check condensate line
and flue gas system for leaks.
Check ignition cable resistance
(4.5K to 5K Ohms).
Check flue gas system for leakage
(flue gas recirculation), check
running gas pressure.
Fault F9 after
approximately
51 seconds.
Fault F4
Fault F4
Fault F4
Burner shuts off when
the boiler temperature is
below the selected boiler
set-point temperature
and immediately starts
up again(cycles).
Corrective action
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yes
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no
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