Safety Systems; Float; Overflow Channel; Water Inlet Valve - Bosch SHEM63W55N Repair Manual

Design and function

3.10 Safety systems

Several safety systems in dishwashers guard against leaking. Leaking water is directed
into the base where it's detected by the float switch, which stops the wash cycle, turns
off the water valve (if it's on) and turns on the drain pump.
Even when the dishwasher is off, the float switch detects water, turning on the drain
pump and generating an error code (e.g. E:15). The dishwasher cannot be run until the
leaky part is fixed, the water is removed from the base and the control is reset.

3.10.1 Float

The float is a safety device, located next to the sump, which activates if there's too
much water in the base. If water collects in the base, a styrofoam float rises and en-
gages a microswitch, stopping the wash program and starting the drain pump.
Fig. 44: Float and float switch location and details
1 Float assembly with float switch
2 Float

3.10.2 Overflow channel

The overflow channel (gutter) directs any water escaping past the door into the base
where it's detected by the float switch.
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Fig. 45: Overflow channel
1 Overflow channel
2 Support / drain tube

3.10.3 Water inlet valve

Starting FD 9807, water inlet valve holders were changed to remove drains, providing
better protection from leaking since its better clearances allowed water inlet hoses to
be more securely connected.
Fig. 46: Water valve holder w/o drain
Before FD 9807, water inlet valve holders had a drain channel to direct any leaking wa-
ter to the base to be detected by the float switch.
Fig. 47: Water valve safety drain
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