Air Conditioning - **please please help*** ac freezing....

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hockey4418
10-10-08, 06:45 PM
Thank you for reading this post.

My Air Handler has recently been freezing. Reading these posts, I thought my handler could be dirty so I had the coils cleaned and a bit of freon.

Days later it froze again. The technician came out and the freon was not leaking and the pressure was normal. Thinking it was the contacts on the condensor outside, I had them replaced.

Days later it froze again. Cleaned the coils, no leak, perfect pressure, new contacts..Both the condensor and air handler work in conjunction until the air handler freezes and the condensor outside only turns on.

So any ideas guys? Thermostat? Contacts inside? Blows great cold air and their trying to sell me a new set up. Any any any help would be greatly appreciated.

Thanks


Jay11J
10-10-08, 07:13 PM
You or someone been home to watch the outdoor unit to see if it shuts down or not when the indoor unit is not running?

What are you temps inside and outside, and how cool do you set your stat at?

Not sure where you are out of, but the nights are cooler now, and where I am, (minnesota) I haven't had our A/C on over a month since it's been very cool out now.

hockey4418
10-10-08, 08:11 PM
Thanks for your reply. To answer your questions..
I've been able to run back and forth and see that the condensor only turns on when the air handler/thermostat tells it to. Once upon a time that was a problem and it resulting in purchasing a new capacitor for the condensor.

Currently its being kept at 79 and to be living in miami, florida...its hot! I'm afraid to have it lower.

Unfortunently this is a topic that I know nothing about and hope through these threads, I can determine the problem.
Thanks again.


mike n
10-10-08, 09:00 PM
So if your outdoor unit is shutting off when the stat tells it to that leaves us with air flow. Is your indoor fan quitting or is your air blocked either on the return side or supply. Is there alot of negative pressure on your system (your filter being sucked in very tightly) this means the air has a place to go (plenty of supply) but the return is restricted. Is there almost no negative pressure (no air pulling on your filter) this means there is no place for the air to go (fan too slow or supply restricted.)
Either it is air flow or whoever is reading your pressures is not reading them correctly or is not using a thermometer to check lineset temperatures.

Former Member
10-10-08, 09:30 PM
QUOTE: Both the condensor and air handler work in conjunction until the air handler freezes and the condensor outside only turns on.

After reading that I am going to guess that the air handler blower fan stops blowing THEN the coil freezes. Maybe the technician did his job and took all the readings but the intermittent blower fan in the air handler did not fail while he was onsite? I would swap the t-stat over to the position where the blower fan runs continuos and give that a try. You may just need a blower motor capacitor but if this is a older unit it would be advisable to replace the motor and capacitor. If in fact it is determined that ole former member is right about the fan. Confidence is high I can tell you that.:coffee:

hockey4418
10-11-08, 08:00 AM
Again, First off I'd like to say thank you for those who have read this and responded.

With the little knowledge I have of this topic - I observed more closely when the air handler completly does not turn on. By manually decreasing the temp on the thermostat, all components would work. Once it reached the desired temp, everything would turn off accordingly. When the digital thermostat reconized a need to turn back on, the condensor would turn on, but the air handler wouldn't.
With that said, I thought to myself it could be the thermostat, so I proceeded by switching thermostat to the off position - wait a min - turn it back on - and manually turn it on. Bingo - it turned on.
With this story that I'm typing finally coming to an end, I ran to home depot last night and purchased a new thermostat. Since 10pm last night (i post this 10am eastern), its doing fine. So I'm crossing my fingers and keeping all your suggestions and comments in mind if this is just a coisidence.
Digital programable stats, expensive vs. inexpensive - does it matter?

Thank you again.

sminker
10-11-08, 01:54 PM
the fan wil cycle with it in the AUTO position on the stat and cycle with the condenser outside......in the ON position it stays on no matter what the outside is doing even if the stat is satisfied or even in the off position on SYSTEm.next time the motor shuts down during a cooling run.run down :dogrun: shut the furnace toggle off....and pop the fan cover door touch the fan motor housing if it is hot it might be going off on internal temp stat from th heat during a coling run.does it free spin with the power off