Multiple A/C problems

Old 09-06-19, 11:41 AM
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Multiple A/C problems

No clue if that is the correct spelling of wazoooooooo but that being said I have 3 different air handler units and 2 of them are down. The one downstairs that I have is blowing cold air but the fan will not turn off (unless if I unplug the thermostat). The thermostat has no display (no batteries it is hard wired) but it is still running the system. The wires going to the thermostat have 26 volts to them and the red wire shows continuity to all of them. I installed a new thermostat (this one uses batteries) and still no luck and the system seems to continuously run no matter what I set it at. I could remove the thermostat and it would shut of previously but now it is just continuously running. When I go and look at the unit the light flashes 6 times which according to their description means no ground/reversed polarity. No wires have been switched, no wires have been taken off, the only thing that happened (that I have to assume caused all this) was there was a thunderstorm a few days ago. The second unit I have is 1 of 2 upstairs I am 98% certain that it is because the contractor on the outside unit fried because the 24 volt feed wires show continuity across them. I just have not made it to the roof yet to verify and quite honestly I do not need that one as bad right now. Thanks for any thoughts or inputs you may have.

Last edited by DIY'NG ESQ; 09-06-19 at 12:26 PM.
Old 09-06-19, 05:25 PM
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Welcome to the forums.

Let's concentrate on the one unit first.

It's customary to post a picture of the wires on the thermostat. It eliminates guessing on our part.

A make and full model number of the furnace is also helpful.

If you remove the thermostat and the blower stopped..... it sounds like a stat problem.
Now it keeps blowing without a stat.... you may have an open safety on the furnace.

The red wire is R or 24vAC.
You should measure 24vAC from......
R to C. (common)
R to G. (blower)
R to Y. (a/c compressor)
R to W. (heat)
Old 09-07-19, 05:28 AM
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Hi, if you remove the Tstat wires from the control panel at the furnace,will it shut down?

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