Furnace Thermal Cutoff With Hanging Downward "Wheel", Or ?

[Robert11]

Hello:

Moved into a 30 yr old house with a forced gas hot air heating system.

Saw something near the furnace wiring which I'm not familiar with.

Seems like they have a regular 4 inch square type gang box
mounted in very close proximity to the furnace with what looks
like a threaded rod/stud hanging downward from, with a round wheel on the
hanging stud.

Is this a thermal safety shutoff ?

Who manufacturers them, and what are they "officially" called or termed ?

If so, how does it work; is it likely for the 110 V power feeding the
furnace ?

Would there be any possibility that if this is the purpose, they might have
it wired into the chained together smoke detectors for an indication if it
is
ever tripped ? Did they ever do this type of scheme with smoke detectors
way
back, possibly ?

Or,... ?

Thanks,
Bob

 

[AlanBown]

Hello:

Moved into a 30 yr old house with a forced gas hot air heating system.

Saw something near the furnace wiring which I'm not familiar with.

Seems like they have a regular 4 inch square type gang box
mounted in very close proximity to the furnace with what looks
like a threaded rod/stud hanging downward from, with a round wheel on the
hanging stud.

Is this a thermal safety shutoff ?

Who manufacturers them, and what are they "officially" called or termed ?

If so, how does it work; is it likely for the 110 V power feeding the
furnace ?

Would there be any possibility that if this is the purpose, they might have
it wired into the chained together smoke detectors for an indication if it
is
ever tripped ? Did they ever do this type of scheme with smoke detectors
way
back, possibly ?

Or,... ?

Thanks,
Bob

Descriptions suck rocks

Pictures please and then maybe we can help ya.