Thermistor/Atc Control (Auto Temp) - GE Profile PTWN8055MMS Technical Service Manual

The overfl ow sensor is located near the left side
of the drain pump and is inserted into a recess in
the washer fl oor. Two wires are connected to the
overfl ow sensor. It is necessary to remove the rear
cover to access the overfl ow sensor. (See
step 1.)
Overfl ow Sensor Removed

Thermistor/ATC Control (Auto Temp)

• The ATC control uses a water temperature
sensor (thermistor) to regulate the wash water
,
Top Cover
temperature.
• The thermistor has a negative temperature
coeffi cient (as temperature increases, resistance
decreases).
• The thermistor is located in the bottom of
the outer tub, under the wash basket. (See
Component Locator Views
To determine the temperature of the incoming
water, the washer control measures the difference
between the voltage sent and the voltage returned
from the water temperature sensor. The washer
control then makes temperature adjustments
accordingly.
The washer control should maintain the water
temperature in the tub within +/- 5°F (+/- 3°C) by
opening or closing the hot and cold water valves.
The thermistor has an approximate resistance value
of 56K  at room temperature.
Water Temperature
86°F (30° C)
104°F (40° C)
140°F (60° C)
158°F (70° C)
203°F (95° C)
221°F (105° C)
The resistance of the thermistor can be checked
between the gray and white wires on the power
board white ATC connector. Make sure to unplug
the connector to isolate the thermistor before taking
resistance readings. (See
Locator View.
– 30 –
.)
Resistance ± 5%
39.5 K Ω
26.1 K Ω
12.1 K Ω
8.5 K Ω
3.8 K Ω
2.8 K Ω
Circuit Board Connector
)
(Continued Next Page)