Miele W1903 - Non-Return Valve & Drain Venting

Technical Information
W1900 Series Clothes Washers
4.12 Non-Return Valve & Drain Venting
Refer to Figure 4-5 – Non-Return Valve.
During the drain segment of a program the Ball-Seat Valve, (item 1)
closes preventing dirty water from re-entering the Suds Container. Should
the drain connection on site be lower than the water level (within the
appliance) the valve opens to prevent any siphoning of water from the
appliance.
Figure 4-5: Non-Return valve
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