Error code · Dryer

ASKO T731 Dryer Code F4: Overheat Protection Tripped

F4 on an ASKO T731 dryer, an older model with an LED display, means the overheat protection device has activated. This is a safety device that shuts the heat off when the air inside runs hotter…

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Code: F4
Appliance: Dryer
Brand: ASKO
Warranty: 30-day workmanship

What F4 means

F4 on an ASKO T731 dryer, an older model with an LED display, means the overheat protection device has activated. This is a safety device that shuts the heat off when the air inside runs hotter than it should. The owner's manual points first to the lint filter, because a clogged filter restricts airflow and lets the heat build up. The dryer stops the cycle and shows F4, and it is an older model we still repair.

Common causes of F4

A lint filter clogged with lint
A crushed, kinked or blocked exhaust duct
A temperature sensor or thermostat that is not controlling the heat
Heat building up because of restricted airflow in the vent hood

✓ One safe check you can try

1. Let the dryer cool down completely before you touch anything inside the door. 2. Clean the lint filter thoroughly. 3. Run the dryer again, as the owner's manual directs. 4. If F4 returns, do not use the dryer again until we have checked it.

! Why to stop there

Whether the vent run to the outside is clear along its whole length
Whether the heating control is switching off at the right temperature
Whether the protection device has been damaged by repeated overheating

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" E7ASKO Dryer Code E7: Control Cannot Read the Door Please empty the condensation tank before resuming a cycleASKO T5 Dryer Message "Please Empty the Condensation Tank Before Resuming a Cycle" E8ASKO T5 Dryer Error E8: Button Input Error E9ASKO Tumble Dryer Code E9: Software Versions Do Not Match F1ASKO T731 Dryer Code F1: Call for Service Message

F4F4 questions

Why does the overheat protection trip?

It trips when the air inside gets too hot, most often because airflow is restricted. A clogged lint filter is the first thing to check, and then the exhaust duct and outside vent hood.

Is it safe to keep running the dryer with F4?

Clean the lint filter and try one cycle only. If F4 comes back, stop and do not keep restarting. Repeated overheating is a safety concern and can damage the dryer.

Can you repair an overheating T731?

Yes. Some older parts are scarce, so we confirm parts first. To set up a visit, call us or fill in the online form. We put the price in writing before work begins, and we stand behind the repair with a 30-day workmanship warranty.

Book a visit

Still seeing F4?

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

(713) 804-6320