Frigidaire Dryer High Limit Thermostat Tripping:... | appliancefaults.com

Technical Background:

The high-limit thermostat is a safety device designed to protect the dryer from overheating. When the temperature inside the dryer exceeds a certain threshold, the thermostat trips, interrupting the power supply to the heating element. The MCU (Main Control Unit) relies on the thermostats to signal it when temperatures get out of range, allowing it to act before major damage occurs.

Symptoms:

The dryer runs for a short period, then stops. It may restart after cooling down. Clothes take longer to dry, or the dryer may not heat at all. A burning smell might be present.

Possible Causes:

Restricted exhaust vent.
Clogged lint filter.
Faulty blower motor.
Defective heating element.
Improper dryer venting system.

Solution:

1

Unplug the dryer from the 120V AC outlet. Lock Out Tag Out (LOTO).
2

Disconnect the dryer vent from the back of the unit and inspect for blockages. Clear any obstructions.
3

Remove the lint filter and clean the lint filter housing using a vacuum cleaner.
4

Access the blower housing (usually requires removing the front or rear panel). Check the blower wheel for obstructions. Verify the blower motor spins freely.
5

Using a multimeter, test the heating element for continuity. A reading of around 9-13 ohms is normal. An open circuit indicates a faulty element.
6

Inspect the high-limit thermostat itself. A multimeter should show continuity. If open, the thermostat is likely tripped or defective and needs replacement. Use a 1/4-inch nut driver to remove.
7

After replacing any faulty parts and ensuring proper venting, reassemble the dryer and test its operation. Monitor for further tripping.

Safety Warning:

Always disconnect power to the dryer before performing any repairs. High voltage is present inside the dryer. Lock Out Tag Out (LOTO) procedures must be followed to prevent accidental electrocution.

Prevention:

Clean the lint filter after every load. Inspect and clean the exhaust vent at least once a year. Ensure proper dryer venting materials are used (rigid or flexible metal duct, not plastic or foil).

Expert Tip:

Some Frigidaire dryers have a service mode that allows you to run diagnostic tests and view error codes. Consult the service manual for the specific model to access this mode. A common sequence involves pressing and holding two buttons simultaneously for a few seconds.

Frequently Asked Questions

•What is the proper length and material for the dryer vent?

The dryer vent should be as short and straight as possible, ideally no more than 25 feet in total length, with deductions for elbows (e.g., deduct 5 feet for each 90-degree elbow). Use rigid or flexible metal duct, 4 inches in diameter. Avoid plastic or foil duct.

•How do I test the blower motor?

Visually inspect the blower wheel for obstructions. With the dryer unplugged, check the blower wheel for free rotation. To electrically test, use a multimeter to check for continuity through the motor windings. If no continuity is present, the motor is likely defective. Also, inspect the motor windings for shorts to ground. A clamp meter can measure the amperage draw of the motor during operation. A higher than specified amperage draw indicates a problem.

•Where is the high-limit thermostat located?

The high-limit thermostat is typically located on the heating element housing. You will usually need to remove the rear or front panel of the dryer to access it. It's a small, round or rectangular component with two terminals.

Frigidaire Dryer High Limit Thermostat Tripping: Symptoms and Fix

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the proper length and material for the dryer vent?

•How do I test the blower motor?

•Where is the high-limit thermostat located?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: