I have the old style thermostat on my AC that is giving me some trouble. I
have played with it a bit and have isolated the problem to the point I think
may be someone can tell me if it can be fixed or have to get a new one.
It is the old style with a mercury bulb inside, the manually adjust a dial
to the desired temperature. There are two switches:
- fan ON or AUTO swicth - I leave it on AUTO
- HEAT OFF COLD switch
Down here in Miami, I pretty much leave the HEAT OFF COLD on COLD. I set it
to 72 degrees and that works fine. If it dips below 72 the AC kicks on.
Last two weeks we had a cold front so I turned on the heat, I might use the
heat once every two year or so, last may be a week here, a week there.
If I set it on HEAT the heat does not kick on no matter how I adjust the
I then removed the cover, and adjust the settings left and right and I can
see the mercury drop rock left and right.
However, if I set the switch from HEAT to OFF, wait 2 seconds, then set it
back to HEAT, if I then adjust the temperature setting I can see the mercury
drop moved to one side and when it hits the wire filaments inside a very
faint spark, and the heat comes on. It stays on until the temperature is
reached then it goes off. It will stay off from now on unless I turn the
switch to OFF and back to HEAT, and adjust the temperature then it will come
Any ideas what is wrong?
Thanks for any comments.