Surfer Thread - Help - If any of you are HVAC certified I have a question...
 

If I set my thermostat on 68 (heat) it comes on 10 seconds after it shuts off, every time, almost constantly. For some reason at that temp., a cold breeze blows around the area the thermostat as soon as the blower shuts off and it cycles back up. If I set it at 70 or 72 it runs fine and stays off for at least a half hour to 45 minutes, and there is no cold air rush when it shuts down. Now, I have some idea of the heat loss rate of the house, and I know there is no way that a few degree difference in the program can have such a large impact on the frequency of the system starting back up. So, what can I do? I have no idea why at 68 the air rush occurs, and I do not know where it is coming from. I know it is happening at this setting though because I am sitting 4 feet from the thermostat and I can feel the air. Is it a thermostat issue, or do I have some kind of pressure anomaly I need to hunt down and cure?

The thermo is a Honeywell digital programable panel, and not mounted within any direct path of a door or window if that helps.

Not a HVAC PRO, but my buddy does AC's for a living and I have worked on a few installs with him. I have a feeling that you are having a pressure prob because air use to flow out the hole that was behind the thermostat and I just caulked the shit out of it.

One problem causing that might be leaking duct work that is forcing air into the attic thus forcing into the wall crevasses...

Interesting. This is driving me nuts. The wall on which the thermo is mounted is completely out of the normal ariflow route of the house. It's only an issue at my programmed setting of 68 degrees that I have this problem. And I agree with you it is a pressure problem. At different "forced" settings I don't have any problems, but anywhere under 70 or so I start to have the problem I am seeing here. I wouldn't care except that 68-70 is comfortable, but with a nearly 70% increase in gas prices where I live, I want to economise wherever I can ths winter, and the temps are already causing an issue.

Bump for a good cause. A quick diagnosis may require more information.

Gas, Electric or Oil Heat?

digital thermostat?

that could be your issue right there. those things are very very problematic

Thanks Steve, the heater is fueled by gas, forced air type.