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Lennox 12ACB48 - Help

5408 Views 57 Replies 9 Participants Last post by  wreedlbz

I recently purchased a home with a Lennox 12ACB48 unit. The unit would not cool very well so the sellers had it serviced and freon was added and fan motor replaced I believe. Vent temps went from mid 70s to 59-64 around the house. Today it was very hot outside (Houston TX) and the unit stopped cooling. It was blowing 84 out of most vents and the compressor was blowing somewhat cool air out the top. I turned the thermostat off and back on after a few minutes and everything seems to be fine for now.

Can anyone help me with what is going on? My uncle a competent engineer came over and put gauges on the system and they were OK he said. I have a service call scheldued with my home warranty, but I trust this site way more than any tech from the home warranty company.

Any ideas as to what is going on?
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How do you know the compressor is off?
Have you check the contactor?
Cap was completely shot, replaced it and so far so good.

post # 2 was the first tip to test the capacitor ...... post # 29 coil was cleaned, and installed hard start kit ........ should have tested the capacitor at the beginning of this post. :furious:
At this point, you need tell us what you did so far to fix this problem.
1- Post some images of the condenser
2- Visual inspection and voltage drop across the contactor
3- Measure motor fan and compressor amp draw
4- You need to test resistance/short to ground of the compressor windings
5- Leave AC running for 15 minutes and check high and low pressures

Let us know the results of these tests
1 - 5 of 58 Posts
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