thermocouple for gas stove

[bromleybysea]

I am in the process of replacing a thermocouple on the hob of a Force 10 cooker. It’s about 25 years old and apparently there are no spares available for these early Canadian-built models. Now made in France. I’ve bought a couple of generic thermocouples off ebay and I’m intrigued to see they come, like the original, with a single wire with a female spade terminal that connects with the gas valve. I’m intrigued to know how these work without any electrical supply?

 

[Boater Sam]

A thermocouple generates a voltage. The resulting current magnetises the solenoid in the gas valve.
The single wire ones use the ground connection through the chassis of the appliance.

 

[DinghyMan]

The heat on the thermocouple and the two different metals inside it creates the electrical supply when heated

 

[greeny]

I am in the process of replacing a thermocouple on the hob of a Force 10 cooker. It’s about 25 years old and apparently there are no spares available for these early Canadian-built models. Now made in France. I’ve bought a couple of generic thermocouples off ebay and I’m intrigued to see they come, like the original, with a single wire with a female spade terminal that connects with the gas valve. I’m intrigued to know how these work without any electrical supply?

If you read the link below you will understand how a thermocouple works. Several different types for different applications. Important you get the right type for the stove application as it's designed to be a safety feature. The millivolts emf generated will vary depending on the metals used in the conductors. Don't think there is such a thing as a "generic" thermocouple. https://temp-pro.com/2022/08/31/guide-to-thermocouples-types-and-uses/

 

[Boathook]

If you read the link below you will understand how a thermocouple works. Several different types for different applications. Important you get the right type for the stove application as it's designed to be a safety feature. The millivolts emf generated will vary depending on the metals used in the conductors. Don't think there is such a thing as a "generic" thermocouple. https://temp-pro.com/2022/08/31/guide-to-thermocouples-types-and-uses/

I've never seen thermocouples like the ones in the link. I would think force 10 would have used a standard cooker thermocouple more than likely available from a reasonable plumbers merchant.

 

[bromleybysea]

I've never seen thermocouples like the ones in the link. I would think force 10 would have used a standard cooker thermocouple more than likely available from a reasonable plumbers merchant.

That's what I'm hoping. Though I suppose I can't complain as the stove is still going strong, it was the same price as a top-of-the-range full-size domestic cooker like a Cannon at the time. Now over £1,700.

 

[Boathook]

That's what I'm hoping. Though I suppose I can't complain as the stove is still going strong, it was the same price as a top-of-the-range full-size domestic cooker like a Cannon at the time. Now over £1,700.

Just reread your original post and I don't think that I have seen a thermocouple with a wire and small spade terminal.
The connection I'm more used to is a thread like the one pictured. Ignore the white wire as is is part of an oxygen sensor from a gas boiler.

 

[Ian_Edwards]

I have a Force 10 cooker from 2007. It could be about the same age as your.
It uses the same single spade terminal.
I bought 3 from:

www.penguineng.com

Penguin Engineering Ltd
Unit 3 Hayling Billy Business Centre
Furniss Way
Station Road
Hayling Island
Hants
PO11 OED

In November 2024.
Not cheap for what they are, and as others have said, they are probably a standard part used in other products. However, I have tried and failed to find an alternative supplier.
I've found that the 3 hob thermocouples last 3 or 4 years, but the 2, oven and grill, are still original, probably because they used much less often.
I've also found that contacts just behind the control know, which activate the spark ignitor bend over time and stop working.
If you take it all appart, you can bend them back with needle nose piliers.
However, taking hob apart is time consuming, lots of small screws and bolts, but at least it built so that you can maintain it .

 

[greeny]

I've never seen thermocouples like the ones in the link. I would think force 10 would have used a standard cooker thermocouple more than likely available from a reasonable plumbers merchant.

The link was to inform how a tc works and the reason to get the correct type, not to suggest a direct replacement.

 

[bromleybysea]

I ordered a "generic" thermocouple from eBay. Eight quid. It was a bit larger than the original so I had to drill out the hole in the burner a couple of mm to accommodate, but it worked fine.