Kenmore Dryer F23: Exhaust Thermistor Short Circuit

The Opposite of F22

Your Whirlpool-built Kenmore dryer (model prefix 110.xxxxx) displays F23 and stopped heating. F23 is the complement of F22 — where F22 means infinite resistance (open circuit), F23 means abnormally low resistance (short circuit). The board interprets near-zero resistance as an impossibly high temperature reading and shuts down heating as a safety precaution.

NTC thermistors decrease in resistance as temperature rises. When resistance drops below the minimum expected value — lower than even the highest safe operating temperature would produce — the board concludes either the sensor has internally collapsed or the dryer is dangerously overheated.

Check Your Model Prefix

This code applies to 110.xxxxx Kenmore dryers (Whirlpool-built). Model prefix 796 (LG) or 417 (Frigidaire) means a different manufacturer with different error codes.

Why F23 Occurs

Internal Sensor Collapse

The NTC thermistor's ceramic semiconductor element can develop internal micro-cracks from thousands of thermal cycles (heating to 200+ degrees F during operation, cooling to room temperature between loads). These cracks create a low-resistance path through the material. At room temperature, a shorted thermistor reads under 1K ohms instead of the normal 10K-50K ohm range.

Pinched or Chafed Wiring

If the two thermistor wires chafe through their insulation and touch each other — or if both conductors contact the grounded metal frame simultaneously — the board sees near-zero resistance. Look for bare copper visible at points where wires cross sharp sheet metal edges, are secured too tightly by cable ties, or pass close to the heating element.

Water or Condensation

Moisture on thermistor connector pins can create a low-resistance bridge between the two conductors. This is more common in humid laundry rooms or after extended periods of non-use (condensation accumulates). Dry connectors with compressed air and apply dielectric grease.

Genuine Over-Temperature (Check This First)

F23 can indicate real overheating from a severely restricted exhaust vent. Before replacing the thermistor, check the entire vent system — lint screen (including for invisible dryer sheet residue), lint trap channel, internal duct, external vent duct, and exterior hood. If the vent is restricted, fix the vent first. A new thermistor in a dryer with blocked vents will trigger F23 again once the dryer reaches genuine over-temperature.

Testing the Thermistor

1. Disconnect power
2. Remove the back panel
3. Locate the thermistor on the exhaust duct
4. Unplug its connector
5. Measure resistance: expect 10K-50K ohms at room temperature
6. Under 1K ohms = shorted sensor
7. If sensor reads normal, measure between each wire and the dryer frame — any low reading indicates insulation breakdown

Thermistor replacement: $10-$25. Installation: 10-15 minutes.

The Critical Vent Connection

Always check the exhaust vent system when F23 appears, regardless of what the thermistor test shows. F23 from a genuine over-temperature event means the dryer was operating at dangerous temperatures before the safety shutoff engaged. A sensor replacement without vent service leaves the fire hazard in place.

If the dryer smelled hot, felt unusually warm on the outside, or clothes came out extremely hot before F23 appeared, the vent is almost certainly restricted. Clean the full vent path, then retest the thermistor.

F22 vs. F23 on Kenmore 110-Series

Cost Summary

Questions About Kenmore F23

Is F23 more dangerous than F22? Potentially yes — F23 can indicate genuine overheating from a blocked vent, while F22 simply means a disconnected sensor. Always check the exhaust vent system when F23 appears before concluding the sensor is faulty.

The dryer smelled hot before F23. Is the vent blocked? Most likely. The hot smell confirms genuine over-temperature conditions existed. Clean the entire vent system from lint screen through exterior hood before replacing sensors.

Can a new thermistor fix F23 if my vents are clogged? Temporarily — until the new sensor detects the same real over-temperature. The clogged vent is the root cause. Fix the vent first, then reassess whether the thermistor also needs replacement.

F23 appeared during the first load after vacation. What happened? Condensation may have accumulated on the thermistor connector during the extended idle period, creating a low-resistance bridge between pins. Dry the connector with compressed air and apply dielectric grease.

F23 on your Kenmore dryer? We test the sensor and inspect your exhaust system — addressing both the immediate fault and any underlying vent restriction. Book your repair.