Error code · Dryer

ASKO T731 Dryer Code F3: Thermistor Problem

Medium · inspection needed

Code: F3
Appliance: Dryer
Brand: ASKO
Warranty: 30-day workmanship

What F3 means

F3 on the ASKO T731, an older dryer with an LED display, points to the thermistor, the small temperature sensor that tells the control how warm the air inside the dryer is. The owner's manual lists it as a thermistor problem and asks you to call a technician. Without a usable temperature reading, the dryer cannot manage its heat, the cycle ends and F3 appears. We repair this older dryer.

Common causes of F3

The thermistor failing to report a usable temperature
Wiring or a connector between the thermistor and the control
The control board that interprets the sensor signal

✓ One safe check you can try

1. Switch the dryer off at the control, count to sixty, and switch it back on. 2. Make sure the lint filter is clean and the vent is not crushed or blocked. 3. Try a short cycle to see whether F3 comes back. 4. If it does, keep the dryer off and arrange service. Do not remove any panels.

! Why to stop there

Whether the sensor itself or its wiring is the weak spot
Whether the control reads a good sensor correctly
Whether a T731 part is still available, which we check before writing the price

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Dryer codes

Protection enabled (screen lock)ASKO T5 Dryer Message "Protection Enabled (Screen Lock)" SENSORASKO T761 and T781 Dryer Message "Sensor" THERMISTORASKO T761, T781 and TD70 Dryer Message "Thermistor" NO ERROR CODESASKO T711 and T721 Dryers: No Error Codes in the Manual OVERFLOWASKO T781 and TD70.3 Dryer Message "Overflow" E3ASKO Dryer Code E3: Pump Not Moving Condensate PLEASE CLOSE THE DOORASKO T5 Dryer Message "Please Close the Door" E6ASKO Tumble Dryer Code E6: A Control Switch Did Not Respond

F3F3 questions

What is the thermistor in my T731?

It is a temperature sensor in the airflow. The control relies on it to keep heat in a safe range, so a missing reading stops the dryer and shows F3.

Will cleaning the lint filter help F3?

It is a good habit and costs nothing, but F3 is about the sensor circuit rather than airflow. If the code returns after you clean it, the sensor needs testing.

Is it worth fixing an older T731?

Often yes, and we will say so if a repair costs more than the dryer is worth. Ready to book? Call us or fill out the online form, and we will give you a three-hour arrival window. Nothing starts until you approve the written price, and the work carries a 30-day workmanship warranty.

Book a visit

Still seeing F3?

A technician diagnoses it on site and gives you the price in writing before any work starts.

(713) 804-6320