PDA

View Full Version : Thermostat losing power briefly


jlevitt
Oct 14, 2010, 01:15 PM
I just bought my first home and am having an odd issue with the furnace/thermostat. The issue is the following. The heat pump is heating the house, then the thermostat calls for more heat and the gas furnace kicks in. So far all is well. When the gas burners shut down (I hear some relay or something at the furnace) it cuts the 24v that goes to my thermostat, so my thermostat loses power. It stays like this for 30 or 40 seconds and then I hear another click and power is restored to my thermostat (the fan continues to operate even when the thermostat loses power). SO... why am I having voltage failure ONLY when the gas burner cycles off? Is it a relay issue, a transformer issue, a wiring issue? Thanks!

dmekuria
Feb 15, 2011, 02:34 PM
I was having the same problem and I found your quote online to be similar to mine. I did two things and the problem was fixed although I don't know which one of the two fixed them because I did both of them at the same time. The first thing was I checked the air filter and made sure the filter wasn't extremely dirty and put in properly (the arrows going in the same direction of air flow). The second thing I did was adjust the gas pressure. Although this is not normally recommended for novices, I didn't know what it was when I first adjusted it. I accidentally cut it off and the furnace wouldn't ignite although the blower kept blowing, however the thermostat didn't cut off. I didn't know what happen and thought I broke the furnace or something.lol! Then I read the instruction manual and learned what the gas setting is and how it should be on. I put it on full blast and it started short cycling with power outages. I adjusted it because of something I read online scared me.. "You should never adjust the gas pressure, only 1/4 inch" and thought to error on the side of caution and turned it down to about 30 degrees from the on position. After turning it down and re-installing the filters again, the thermostat stop powering down. It seems to work find now. I'm presently monitoring it.