New 410 Rheem not cooling -- coil seems ok but how to check compressor?


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Old 07-22-13, 12:44 PM
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New 410 Rheem not cooling -- coil seems ok but how to check compressor?

Can someone tell me what the pressure and temp numbers should be? Or what a good tech would check in this situation?

I had a new Rheem split system with new line set installed in April. My condenser is Model 14AJM49A01 with a matching cased coil RCFLHM4821CC. The compressor is 50 ft and 6 ft higher than coil.

During our first heat wave (over 90 for a week) in June, it kept the house comfortably cool at 73. We are in the middle of our second heat wave, the inside temp got up to 80 and more humid than in June.

The suction line as it came out of the evaporator coil is cool but not as cold as it was in June. The liquid line as it went into the evaporator is warm but not hot (maybe 105). I think the evaporator coil is doing its job, but I know having liquid still in the line when it leaves the evaporator can damage the compressor. And I wonder if that happened between June and July but how can you tell?

The installer (1 yr guarantee) put gauges on the outside condenser and said it was okay. He did not give me any numbers and treated me like I was a 10 year old. The manual said to put a temp gauge on the liquid line 6" from the condenser but he did not do that. He is coming out again, but I wanted to educate myself first so I know what to look for. I don't want to call in a different company and have to pay for the visit.

I tried looking in the manual but I do not understand what the terminology means so I don't know where to look. I looked online and it seemed that super-heat was the most important, but I am not sure I understand what this is and how can it be calculated?

Can someone tell me what the pressure and temp numbers should be? Or what a good tech would check in this situation?
Thanks
 
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Old 07-22-13, 02:37 PM
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That system should be under warranty from the installing contractor.... I recommend you call them back instead of touching or doing anything else.

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Old 07-22-13, 04:02 PM
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I had the installer out and he was the one that said the temp/pressures were okay. When I asked him what they were, he just said they were okay again. He washed off the compressor (one side was a little dirty but the other 3 were clean -- it is a new unit so it was not bad) and left.

I told him the line out of the evaporator was warmer than normal because I had felt it myself when it was working okay so I had a comparison. The evaporator seems to be doing its best, but it cannot cool unless there is a pressure change (and temp change).

I do not want to touch the compressor (or evaporator), but something is definitely wrong.

I want to learn what questions to ask him and to verify that what he is doing will locate the problem.

I also think that the exhaust temp of the air coming out of the top of the condenser is not as hot as it was before.

How can I tell if he is doing the right things? And if the numbers are right, then what could be causing the lack of cooling?

This is a new system, but I had a less-efficient r22 unit that worked fine, so it is not the ducts, and the furnace fan is working so it is not that. The filter is new.

Help! I am desperate!
thanks,
 
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Old 07-22-13, 04:09 PM
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Measure the temp drop (return to supply and ambient outdoor to condenser output). Is your filter clean?

If you have to then you should hire a different contractor and get a second opinion and take that to the original contractor.
 
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Old 07-23-13, 07:48 AM
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Yes, new filter.
The "return to supply" is the large gas line back to the condenser?

Does the other number shows the effectiveness of the compressor?

thanks for your help
 
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Old 07-23-13, 01:37 PM
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When the AC pro comes again, simply tell him you want the temp drop at least 16 or 17 degrees. (don't take any excuse if the drop is not 16+)
 
 

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