OT: idohvac2, question from a clueless AC user

[WBHarrison88]

I'm having an issue with my AC unit and thought you might be able to shed some light on it for me. I have
a split unit (I think that's what it's called). Recently the AC will not turn off on its own. It will
continue to run to the point where the pipes freeze up. One day the air stopped blowing for the most part.
I could hear the unit on and the outside fan was running but hardly no air flow. The coils were frozen up inside
as was the outside pipe near the fan. I let them thaw out for hours and it eventually started working. I Called an
AC repairman and he said the units looked fine that it had to do with my thermostat. He said I could get a new one
and it would fix the issue, he even suggested that I could probably do it myself.

My questions are.. does this sound correct to you? I know you stated before about animal hair getting caught up in
the indoor coil. I have 2 cats so this could add to the issue I assume. Secondly, is changing a thermostat really that easy?

 

[idohvac2]

Originally posted by WBHarrison88:

I'm having an issue with my AC unit and thought you might be able to shed some light on it for me. I have
a split unit (I think that's what it's called). Recently the AC will not turn off on its own. It will
continue to run to the point where the pipes freeze up. One day the air stopped blowing for the most part.
I could hear the unit on and the outside fan was running but hardly no air flow. The coils were frozen up inside
as was the outside pipe near the fan. I let them thaw out for hours and it eventually started working. I Called an
AC repairman and he said the units looked fine that it had to do with my thermostat. He said I could get a new one
and it would fix the issue, he even suggested that I could probably do it myself.

My questions are.. does this sound correct to you? I know you stated before about animal hair getting caught up in
the indoor coil. I have 2 cats so this could add to the issue I assume. Secondly, is changing a thermostat really that easy?

A few things. You state the AC will not turn off on its own, and will continue to run until the pipes freeze up. You will need to find what is happening when it does this? Is the indoor fan still running, but the unit freezes up? Does it stop if you turn the T-Stat to off? Is the T-Stat at a temp that it should be off?

Most likely scenarios:
Low Freon charge
Dirty indoor coil
Indoor fan motor not running (motor, capacitor, relay issues)
Outdoor contact sticking
Is it possible it is the thermostat? Yes. Is it likely,? No

If he is saying that the unit looked fine I am assuming he already put gauges on and checked the charge and it was good. If that is the case, then most of the time the indoor fan motor is not running properly. Bad relay, motor overheating/going bad, capacitor, etc.

Going back to the T-stat. Probably 50% of homeowners change one out themselves and everything goes perfectly. About another half of those just got lucky. This is especially a problem when replacing a T-Stat on a heat pump. It has a reversing valve(the thing that switches the unit from Hot to Cold), and some energize the valve on heat, and some on cool. Also, there are different types of T-Stats for different heat pumps. Getting the right T Stat is a big problem right off the bat. Lowes and Home Depot sell tons of Heat Pump T-Stats that will not work with most Heat Pumps in this area. I just worked on a fellow TI members unit earlier in the year that had the problem with having the wrong T-stat. It would not work no matter how it was wired even though it says for Heat Pump use. It was not the owners fault that the advertising was misleading.

If you would like to really get after this yourself in depth, shoot me an Email to [email protected] and we will exchange #s and I will talk you through everything you can check yourself. It would be a lot of back and forth typing now with questions and answers. I would be glad to help you tho. Especially if you have time to trouble shoot it in the morning.

 

[idohvac2]

Also gonna say if the repair man suggested you could probably change it out yourself, he did not know for sure what was wrong with it, and hoped he would not see it again. My apologies if t is a friend. Nothing more than a solid guess here

 

[Trading Tiger]

He's not the only one with A/C problems, I came to ask a question myself.

I came home from work and immediately noticed it was hit in the house. T-stat reading 82, it's set on 74. Plenty of air was blowing out of the vents, but it was just kind of cool instead of cold. Is this just a low freon issue, and if so, how much am I looking at spending to get it charged? Could it be something else?

Thanks.

 

[patricm]

I just had the same issues. Mine was a bad realay and my heat strips were on while I was running tyhe AC. Power bill was up $300 before I had it fixed.

 

[idohvac2]

Need some more info trading. You stated that air was blowing well in the house. Was the outdoor unit running? If it is a split unit, and is running, what is the temp of the larger copper pipe going in the wall. Is it cold, outdoor temperature, or frozen?

 

[Trading Tiger]

Originally posted by idohvac2:
Need some more info trading. You stated that air was blowing well in the house. Was the outdoor unit running? If it is a split unit, and is running, what is the temp of the larger copper pipe going in the wall. Is it cold, outdoor temperature, or frozen?

I guess I'm even more clueless than the OP. The outdoor unit was running, at least it sounded like it was. Don't know what a split unit is??? I didn't check anything outside, it wouldn't have done any good because I wouldn't even know what I'm looking at.

Ive got someone looking at it right now, but thanks for the response. I'll let you know if I have any other questions or issues.