I've got a few thermostats I need to test

I've forgotten.. how do I test them
and what indicator will tell me when they are bad?
I see no visible cracks and they all can be pushed/accordianed... together.

brant

Heat gun works great but only test them in the bracket.

Or hair dryer...both on low setting...

as mentioned do this on the bracket as you can actually pop/crack the bellows...it will expand beyond it's limits and break

if working it will expand to the limits of the bracket

It defaults to open if it is bad. Just give it a look, closed is good.

thanks everyone.
all 3 of them are in the bracket and show about 1/2 inch of space
I'll heat them (on low) tonight and verify
thank you!

brant