Bedienungsanleitung Steuerung S4_2006_09_25-neu.doc
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Month of issue xx/200x
Art. no. 950 281
9.11 Inspecting the suction pipe and air flow sensor (all models)
Important note: If the stove is connected to an external combustion air pipe, you should
first inspect this pipe along its entire length for any blockage before inspecting the
suction pipe and air flow sensor. This is to establish whether the suction pipe and air flow
sensor are at all times supplied with a sufficient flow of combustion air. The combustion air pipe
must be completely cleared of any foreign matter or deposits (such as lumps of dust).
Combustion air pipes should always be arranged such that their opening outside the building is
protected against wind pressure.
Having checked the combustion air pipe inspect the suction pipe and air flow sensor that
are located directly next to the appliance. Use a mirror and torch to look inside the
suction pipe. There are 2 things to look out for.
1) Check air flow sensor (LMS) for dust / fluff
The sensor and suction pipe must be free of dust and fluff. If this is the case, you need to clean
neither the air flow sensor nor the suction pipe. Only dismount the air flow sensor and clean
it together with the suction pipe if you find dust deposits or bunches of hair or the like (see next
chapter for dismounting instructions).
2) 2) Check air flow sensor (LMS) for soot or blackening
If the sensor shows no signs of soot, it should be in order. There is no need to clean the air
flow sensor and the suction pipe. Only if the sensor shows soot or even signs of blackening
should it be dismounted and cleaned gently using a paint brush and soft cloth. These are signs
of external trouble and/or insufficient cleaning with resultant flow reversal in the suction
pipe. It is essential to find and rectify the cause of the external disorder (see also Chapter
0). It is also advisable to carry out a brief functional check* to determine whether the air flow
sensor is still working properly.
*Brief functional check of the air flow sensor: Open door while stove is in operation. The stove should shut down
within approx. 20 s, with the display showing “LO L-“, and then start up again when the door is closed. Alternatively,
you can have a service technician do a complete functional check, i.e. check the resistors of the air flow sensor
and replace the sensor if necessary.
Note:
Never clean the air flow sensor when mounted and don’t clean it with a brush or the like.
This could destroy the sensor electronics. Observe the instructions in the following
chapter.
air flow sensor (LMS)
Inspect air flow
sensor with a
torch.
mirror
suction pipe
Direction of flow
