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Inlet Control Thermistor
The inlet control thermistor is located on the top
right side of the inlet duct. The thermistor monitors
incoming air temperature and relays the information
to the control board.
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temperature increases, the thermistor's resistance
decreases.
Inlet Control Thermistor Approximate Resistance
Values:
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Operation of the inlet control thermistor can be
checked by using the inlet thermistor test in service
test mode. (See the Service Test Mode section.)
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thermistor can initiate fault codes F01 and F03. (See
the Service Test Mode section in this guide.)
To access the inlet control thermistor, it is necessary
to remove the rear bulkhead for front service, or the
back panel for rear service.
The thermistor is attached to the inlet duct with a
Phillips head screw. A wire harness is connected to
the thermistor.
NOTE: Electric model safety and high limit
thermostats are not located on the air duct.
Gas Model
High Limit Thermostat
On electric models, the high limit thermostat is
located near the back of the heater housing, on the
right side. On gas models, the high limit thermostat
is located on the top right side of the inlet duct,
between the inlet thermistor and the inlet safety
thermostat. The thermostat monitors incoming air
temperature.
If the thermostat reaches a temperature beyond its
maximum temperature rating, it will trip and disable
power to the heating elements (electric model) or
burner assembly (gas model).
The high limit thermostat opens at 300°F (149°C)
and will automatically reset at 270°F (132°C).
To access the high limit thermostat, it is necessary
to remove the drum (electric model). On gas models,
remove the rear bulkhead for front service, or
remove the back panel for rear service.
The thermostat is attached to the heater housing or
inlet duct with a Phillips head screw and a tab. Two
wires are connected to the thermostat.
Electric Model
Gas Model
Inlet Control Thermistor
High Limit Thermostat
High Limit
Thermostat
