Carrier 38EV024320 User Manual
Page 19
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ERROR CODE #5 - INDOOR THERMISTOR FAILURE
REASON: CONTROL BOARD READS TEMPERATURE ABOVE ISCTF OR BELOW -SCTF.
POSSIBLE CAUSES:
1) Thermistor failed or out of calibration (see Note 1).
2) Loose or corroded connection.
3) Faulty control board, Interface board or cable.
Reference Figure 22
Notes:
1) If thermistor Is out of calibration, it may read accurateiy with system off, but may drift from actual
temperatures during operation.
2) For furnace appiications - Remove furnace access panei and tape kili switch so that panel can later be
removed for blower inspection without breaking power.
Reinstall access panel.
3) Adjust thermostat 4°F or more above or below room temperature, depending on mode, to force system
to fuli speed.
A87477