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Error code reference

Kenmore Dryer Error Code EF1

Vent blocked; high vent restriction, Exhaust Control Thermistor, Inlet Control Thermistor, or Electronic…

Kenmore codesKenmore dryer codes

Vent blocked; high vent restriction, Exhaust Control Thermistor, Inlet Control Thermistor, or Electronic Control Board defective.

First step from the service manual

Check vent restrictions and resistance values of Exhaust Control Thermistor and Inlet Control Thermistor.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What EF1 means on a Kenmore dryer

The EF1 error code on a Kenmore dryer indicates a problem within the exhaust airflow or thermal sensing system. The control board monitors exhaust temperatures using two thermistors: the Exhaust Control Thermistor and the Inlet Control Thermistor. When airflow is restricted or either thermistor reports values outside the expected range, the board triggers EF1 to prevent overheating. This code covers a broad diagnostic range, meaning the root cause could be mechanical (a blocked vent) or electrical (a faulty sensor or control board).

The most common trigger is high vent restriction. Lint buildup in the duct run, a crushed or kinked flexible duct, or a clogged exterior vent cap can all reduce airflow enough to cause abnormal temperature readings at the thermistors. The control board interprets this as a fault condition and shuts down the cycle. Before testing any components, the full vent path from the dryer outlet to the exterior termination point should be inspected and cleared.

If the vent path is clear and the code persists, the next step is measuring the resistance values of both the Exhaust Control Thermistor and the Inlet Control Thermistor. A thermistor that has drifted out of its specified resistance range or has failed open or shorted will send incorrect temperature data to the control board, causing a false EF1 trigger. If both thermistors check out within spec, the Electronic Control Board itself may be defective and sending or misinterpreting signals incorrectly.

Source: manufacturer service documentation.

Common causes of EF1

  1. 01

    Blocked or restricted exhaust vent

    Wiring / connection

    Lint accumulation inside the duct, a crushed flexible duct section, or a clogged exterior vent cap reduces airflow and causes abnormal temperature readings. Inspect the entire duct run from the dryer to the outside termination point and remove any obstructions.

  2. 02

    Faulty Exhaust Control Thermistor

    Part replacement

    If the Exhaust Control Thermistor has failed open, shorted, or drifted out of its correct resistance range, it will send inaccurate temperature data to the control board, triggering EF1. Measure its resistance and compare to the specified value for this model.

  3. 03

    Faulty Inlet Control Thermistor

    Part replacement

    The Inlet Control Thermistor monitors incoming air temperature, and a failure here produces the same type of erroneous reading that causes EF1. Check its resistance value; a reading that is out of range confirms the thermistor needs replacement.

  4. 04

    Kinked or undersized exhaust duct

    Part replacement

    A flexible foil or plastic duct that has been kinked, crushed behind the dryer, or is too long for the installation creates restriction even without a lint blockage. Replacing it with rigid metal duct and minimizing bends often resolves the airflow issue.

  5. 05

    Defective Electronic Control Board

    Part replacement

    If the vent path is clear and both thermistors test within spec, the control board itself may be misreading sensor signals or generating a false fault. A failed control board typically requires replacement since individual component repair is rarely practical.

See the test procedure for each cause

Frequently asked questions about EF1

What does EF1 mean on a Kenmore dryer?
EF1 signals that the dryer has detected high vent restriction or a problem with one of its thermal sensors. The code can be caused by a blocked exhaust vent, a defective Exhaust Control Thermistor, a defective Inlet Control Thermistor, or a faulty Electronic Control Board. The dryer stops the cycle to prevent overheating. Start by inspecting the full vent path before testing any electrical components.
Will resetting the dryer clear the EF1 code?
A reset may temporarily clear the EF1 code, but it will return if the underlying problem is not fixed. If a vent blockage or a failed thermistor is present, the code will reappear once the dryer runs and the fault condition is detected again. Always address the root cause before assuming a reset has resolved the issue.
How do I fix the EF1 error code on my Kenmore dryer?
Begin by cleaning the lint screen and inspecting the entire exhaust duct from the back of the dryer to the exterior vent cap, removing any lint buildup, kinks, or obstructions. If the vent is clear, use a multimeter to check the resistance of both the Exhaust Control Thermistor and the Inlet Control Thermistor. Replace any thermistor that tests out of its specified range. If both thermistors are good, the Electronic Control Board may need to be replaced.
Is EF1 on a Kenmore dryer a safety concern?
Yes, particularly when the cause is a blocked vent. Restricted exhaust airflow forces the dryer to operate at higher internal temperatures, which increases the risk of overheating and can become a fire hazard over time. Do not continue running the dryer until the vent restriction has been cleared or the faulty component has been identified and replaced.
How much does it cost to repair a Kenmore dryer showing EF1?
If the problem is simply a clogged vent, professional duct cleaning typically costs between $80 and $175 depending on duct length and access. Replacing a thermistor is generally a lower-cost repair, with parts usually ranging from $15 to $50 and labor adding $75 to $150 if a technician performs the work. An Electronic Control Board replacement is the most expensive scenario, with parts and labor commonly ranging from $200 to $400 or more depending on the specific model.

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