Dead or Cutting Out? How to Test and Replace Thermal Cut-Outs

⚠️ SAFETY FIRST: IMPORTANT

Electricity can be lethal. Before attempting any repair, ensure the appliance is fully isolated from the mains power. If you are not confident using a multimeter or working with high-voltage components, consult a qualified engineer. Never work on a "live" circuit.

Did your oven suddenly lose all power mid-roast? It might not be a blown element. Most modern cookers have a "Thermal Cut-Out" (TCO) at the back. Its job is to act like a safety fuse; if the oven gets too hot, the TCO "opens" and cuts the circuit. In this guide, I’ll show you how to test if yours has tripped and how to swap it in under 10 minutes.

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Symptoms of a Blown Thermal Cut-Out

• Total Power Loss: The oven light, fan, and elements all stop working (but the clock/timer might still be lit).

• Cutting Out: The oven works for 10 minutes, then dies until it cools down.

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Testing with a Multimeter (The 0.0Ω Goal)

The TCO is a simple switch. To test it:

1. Isolate Power: Unplug the cooker.

2. Access: Remove the back panel. Look for small circular components with two wires (often blue or white).

3. The Test: Pull the wires off and set your multimeter to Continuity or the lowest Ohms (Ω) setting.

4. The Result: * Good: You should see 0.0 or 0.1 Ohms (and hear a beep). This means the circuit is closed and power can flow.

   • Bad: You see "1" or "OL" (Open Loop). This means the thermostat has "popped" and needs replacing.

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Why did it trip?

Replacing the TCO is easy (just one screw!), but you must ask why it overheated. Check:

1. Cooling Fan: Is the fan at the top of the oven spinning freely?

2. Door Seal: Is heat leaking out and cooking the components at the back?

3. Main Thermostat: Is the main oven thermostat failing to turn the elements off?

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Buy a good Multimeter here on Ebay UK 

With back access panels removed you can see the 2 over limit thermostats

they have blue wires going to them ill show close ups below 

close ups of both upper oven and main oven thermal

over limit cut out thermostats 

Pull of both cables and you can test it for continuity 

it should be very low ohms resistance reading as this is 

just a safety switch and should be on at all times.

testing with a multimeter 0.0 ohms so excellent 

and continuity buzzer is buzzing see video for this 

this one is held in by one screw and the other side fits into a bracket made for it 

this is the unit free from oven and easy to replace 

testing new thermal cut out over limit thermostat prior to fitting 

just one screw so easy to do 

Buy Multimeter here 

see a video of this process below