A/C Cooling Problem - Lennox 12ACB42-5P


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Old 04-30-12, 07:27 AM
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A/C Cooling Problem - Lennox 12ACB42-5P

I have a Lennox A/C outdoor cooling system 12ACB42-5P that was installed on 4-2-2002. My problem is:
On hot days it will quit cooling and I have to turn it off for 30 minutes and let it cool down. When I turn it back on it starts cooling and may not fail again for 60 days?
I have had it checked by technicians 3 times last year and they couldnít find anything wrong. The unitís freon is full. The unit failed 6 times last summer and has failed once this year.

Your help would be appreciated.
 
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Old 04-30-12, 08:16 AM
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Give us a little more info will help: When it stops cooling, does the air still blow into the house ? (may be not cold air) Was the outside fan and compresser still running at that time. Hand touch the large pipe, does it feel cold still ? How about the small copper pipe ?
 
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Old 05-01-12, 01:49 PM
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Clocert - Thanks for your response -

When it stops cooling, does the air still blow into the house ? (may be not cold air)
Yes itís continues to blow hot air into house.

Was the outside fan and compressor still running at that time.
The fan is running but not the compressor. Cool not hot air out of the top of unit.

Hand touch the large pipe, does it feel cold still ? How about the small copper pipe ?

Donít know about these 2 questions but will check the next time it quits.
 
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Old 05-01-12, 02:02 PM
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Does it only happen when it's particularly hot?

Is the outdoor coil clean?
 
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Old 05-01-12, 02:31 PM
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So, the compresser quits. The problem can be the run capacitor or compresser itself. As mentioned, check the condenser coil to see if it is clean, and while the system is running and cooling, hand touch the small copper pipe to see if it is very hot.
 
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Old 05-01-12, 02:42 PM
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Sounds like its just running a long time and getting too hot.
1. Maybe its arcing at the compressor terminals.
2. Maybe the unit is dirty and can't breathe. This would give you false readings on the freon gauge and is my best bet.
3. It is what it is.
 
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Old 05-01-12, 04:34 PM
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If the air comes out of the outdoor unit at an angle (not straight up), the coil is dirty even if it looks clean.
 
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Old 05-01-12, 05:54 PM
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If the air comes out of the outdoor unit at an angle (not straight up), the coil is dirty even if it looks clean.
WHAT? How do you figure that one? The air is blown across a fan. And then it is blown through louvers on some units.
 
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Old 05-01-12, 07:03 PM
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I understand what he means. A lot of the time the air does not blow straight up, but the air seems to roll off and blow at an angle at the condenser. But some units do this naturally and is not always a case of being dirty.
 
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Old 05-04-12, 04:06 PM
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Yup, that's what I was referring to.
 
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Old 05-11-12, 12:03 PM
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Sorry for the delay but I have been out of town,

The outside unit is washed down on a monthly basis and is very clean.
 
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Old 05-11-12, 12:08 PM
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Happens only when it's particularly hot and the unit has to run hard!
 
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Old 05-11-12, 12:11 PM
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Yes it is very clean. Clean it monthly...
 
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Old 05-11-12, 12:14 PM
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: A/C Cooling Problem - Lennox 12ACB42-5P

Clocert - Thanks for your response.
What is the significance of the small copper pipe being hot??????
 
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Old 05-11-12, 12:28 PM
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If the small pipe is too hot (should be just little warm to touch), that means either your condenser coil is dirty, fan is weak, or may be there is a blockage somewhere along the line. Is the large pipe cold ??
 
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Old 05-11-12, 03:55 PM
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Get the charge and compressor amp draw checked.
 
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Old 06-08-12, 06:55 AM
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A/C Cooling Problem - Lennox 12ACB42-5P

Wife said it quit last week while I was out - She turned unit off for 30 min's and it started cooling again?

I change the filter monthly with a decent grade of filter and it's never that dirty but today it was real dirty?????????
 
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Old 06-28-12, 11:45 AM
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New System

What is a ballpark estimate to replace my 3 1/2 ton 13 seer system with a reliable 14-15 seer system(a/c-heat-etc.) Dallas TX

Are there mft's to stay away from?

Thanks,
Jack
 
 

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