help with HVAC - heater


Active Member
Jul 17, 2010
purchased this house last December. one time we came home and it was 80 inside but the them was set to 72. we changed out the batteries in the thermostats and that didnt fix the issue. we would just use the breaker box to turn the heat off and then one day it fixed itself.

now were having the same issue but it constantly runs. this house was built in 2006 so its not an outdated system. all air filters are new, and we put new batteries in the thermostats again. anyone have some ideas?


Right Wing Extremist
TGT Supporter
Nov 7, 2010
Justin, TX
Buy a new thermostat or wire the one you have correctly.
Do you have a heat pump or regular ac or gas furnace?

Shooter McGavin

Active Member
Jul 26, 2012
Free Texas
I would call an A/C tech out, many will do a free diagnostic and estimate. I used to have a similar issue at my last home, after trying everything I knew to do "which ain't much when it comes to HVAC" I finally called a local HVAC guy to come check it out. The air handler unti in the attic had a bad relay and was causing the unit to either not run at all or to run constantly. It was after hours on a weekend during that bad winter we had a few years ago, cost me $135.


TGT Addict
Oct 16, 2012
Ive worked on both my AC and furnance. If youre not comfortable doing so call a HVAC guy.

If you do start replacing electrical parts i advise wiring in a fuse so you dont fry your parts while troubleshooting.

I found an HVAC forum and a tech on there helped me out a lot. I ended up replacing my contactor (electromagnetic switch out on the AC unit) and on the furnace i had to clean out a vacuum switch. I agree checking the wiring on the thermostat is a good first step.

Just be methodical, logical and slow if you work on it yourself. I learned a lot by fixing my own and saved some money. Post some details here. We may have some HVAC guys. I can help with the basics but im far from an expert.


Jan 19, 2013
Terrell, Tx
Sounds like a relay with sticky contacts. If they arced any and welded themselves slightly, could keep it closed. I have a similar issue with the high beams on my little Honda. Have to flip it a few times to get the high beams on sometimes. I have also had contacts in other relays, AC units included, that stick like this. Most interesting was the HUGE breakers we had on our ship that did this. Took several days of removal, dismantling, fixing and rebuilding to take care of it. But USN ingenuity saved the day, because we couldn't get a replacement through our supply chain for weeks. All about the DIY if you can. Just be careful and methodical like has been suggested.


TGT Addict
Jan 24, 2011
Grid 0409
HVAC techs? We just completed the second phase of a remodel which required moving the HVAC enclosure to another part of the house.

The contractor hired a big-name HVAC company to do the job. The company sent out some senior field reps to survey the site and draw up plans.

Senior field rep said they could get it done in two days, tops.

Long and short, it took six days, and after everything was hooked up, the D/S unit blew conditioned air into one room upstairs, and the U/S unit blew conditioned air into a downstairs room, and the techs found both units low on refrigerant.

Just because they have fancy vans, smart phones, and shoe coverings does not mean they will get it right the first time.

Familiarity with the English Language would be a plus.
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