Temperature drops but thermostat reading rises

gbekurs

My thermostat turns on the a/c, and the temperature in the house drops, but the temperature reading on the thermostat actually rises, which means that the a/c doesn't turn off. I replaced the thermostat, thinking this would solve the problem, but it didn't. The same thing happens with the new one. I felt the wall around the thermostat and it doesn't feel warm. Any idea what's happening, or any suggestions? Thanks.

Ralph III

Well some of the pros will chime in but I have a question.

Did you relocate the thermostat from where it was originally? I would assume this hasn't always been a problem?

If so, it's possible you may have located it in a poor area. Maybe it is by a window or door and a draft is being created when the system is on, thus pulling in warmer outside air?

I cannot figure any other sceneario considering the tstat just measures the surrounding air temperature. If it's going up, as you state, then you have to be circulating warmer air past it. Does it never go down or is it just slow in going down?

Good luck

gbekurs

Thanks. I just bought the house, so I don't know whether this was a problem previously. I think the thermostat has been in the same place since construction (30 years).

biggles

did you put your nose/face up to the opening on the wall where the wires come out of to see if there is draft.feeling the wall won't tell anything tape over the hole 2-3 strips of tape then reinstall the subbase