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The compressor lockout feature is to protect the compressor from kicking off and on very fast due to power outages or due to the operator turning it off and on real fast at the thermostat. It will flash this for 5 mins and then it should kick on. If your thermostat flashes this for more than 5 mins then there is a problem with the 24v signal to the thermostat most likely due to a safety cut off device installed on your system like a condensate pump or a safety pan float switch.
Thanks for the quick answer.
I have another theromostat (for a different unit) just like the one that is showing the flashing cool. Would plugging that one into the same slot as the 'bad' one narrow it down to one of the options you described? If that's not the issue are there any other things I can try to override the cutoff?
you can try that it is not unheard of that the thermostat would be bad, but in my experience it is because of a safety device or a loose wire somewhere.
Let me get some information on your system and I can better direct you on what to look for.
Is the furnace in a basement, attic, closet, garage?
Is this a gas furnace on a conventional outdoor A/C or a heat pump system with an electric furnace?
How old is the house and how old is the system?
Furnace is in the attic. It's gas furnace on a conventional outdoor A/C unit. House is 25 years old and the unit is probably 5-6 years old max.
One other thing I forgot to mention...when I pulled the thermostat off the wall the batteries in it were obviously corroded (greenish/white crud on the points). I pulled out the old batteries and scraped out what I could without tearing it up and replaced with fresh batteries. Any chance this could be part of the problem?
yes it could be because the thermostat needs batteries to power the display if there isn't a wire hooked to the C terminal of the thermostat.
Do this real quick and we can determine real fast if it is the thermostat. Take the wire hooked under the Y terminal on the thermostat and place it under the R terminal with the wire already there. This should turn the a/c on bypassing the thermostat. If it still doesn't come on then there is a break in that Y wire somewhere (back to the safety devices)
OK, how do unhook the wires under the terminals. Looks like I just push down on the silver catch and it should lift right out but please confirm.
Also, I took the downstairs (working) thermostat upstairs and plugged it in and it seems to be working. I took the upstairs (not working) thermostat downstairs and plugged it and still get the flashing COOL signal.
I want to check your suggested fix and try to 100% confirm it is the thermostat. Look forward to your confirmation of how to unhook/rehook the wires. Thanks.
any thoughts on how I can clean the current stat to get the gunk off of it? I used an old soft bristle toothbrush and got a lot off but there are pieces of gunk down where I cannot reach without pushing components around.
The stat model is White-Rodger 1f97-371. Is that Home Depot kind of purchase or do I need to get that from an HVAC company? Any idea on what the cost $$ is ? Just finished a kitchen remodel (contractor, not me) and don't have a ton of money to spend.
Do you have an unused wire at the thermostat? Look down in the brown sheathing that all the wires come out of and see if there is a spare.
OK...last questions...I think.
Put 'bad' stat downstairs after some more gunk cleaning and it worked for a minute or two then kicked off with same results as upstairs. It just kicked on again just now but I think it already kicked off again. Should I just turn it off tonight to avoid any damage/issues with the compressor?
Lastly...can I install the thermostat myself? Is it pretty quick to do? Looks pretty simple but I want to get it right. Don't want to leave the wife/kids high/dry here in Hotlanta tomorrow before I have a chance to buy the stat.
I wouldn't leave the compressor kicking on and off like this. You can put the yellow wire under the R terminal with the red wire and leave the front of the thermostat off and the cooling will run the only problem is it will never cut off unless you cut power or pull the yellow wire back out.
The thermostat is a breeze. Just make sure you turn power off to the furnace at the breaker box before you take the wires completely off. Wire it back color for color just like it currently is. Red-R, yellow-Y, ect, ect. You have a 1 heat/ 1 cool conventional system so the thermostat you buy will already be set up for your system you will not have to do any setup menu configurations.
Have a good night over there in Johns Creek, Alpharetta, Milton, or whatever ya'll are calling yourselves these days :)