Drain Pump Assembly; Thermistor - EdgeStar BIDW1802 Service Manual

Drain Pump Assembly

The drain pump assembly is located under the tub and operates on 120 VAC. It is
energized for the first 60 seconds of a new cycle and 90 seconds after the wash pump
shuts down to remove any water in the dishwasher sump. The drain pump forces water
out of the drain line. A check valve flapper on the drain pump prevents dirty water from
reentering the sump. The drain pump has an approximate resistance value of 25- 35Ω.
To remove the drain pump:
1. Disconnect the power.
2. Open the dishwasher door and remove the bottom rack.
3. Lay the dishwasher on its back
4. Remove the 1 screw that attaches the base cover to the base, then use a flat-
head screw driver to release the snap joints.
5. Remove the wiring harness connected to the float switch on the base cover.
6. Rotate the drain pump ¼ turn counterclockwise to remove, which is the opposite
direction of the mark on the sump.
7. Disconnect the 2 wires from the drain pump.
Note: Ensure the O-ring is retained in the pump seal before reassembly.

Thermistor

The thermistor is located under the tub and is attached to the back side of the sump
with two screws. During the hot wash cycle, the thermistor senses the water
temperature and turns the heating element off. The thermistor has a negative
coefficient. As the temperature at the contact point on the tub increases, the thermistor's
resistance decreases. The thermistor has an approximate resistance of
R@25°C=1OΩ±2%; R@60°C=3011Ω±2%.
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