A/C whishing - hissing sound in small line

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  #1  
Old 09-26-07, 04:56 PM
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A/C whishing - hissing sound in small line

Good day to all. I'm noticing a sound like air or fluid going through the small a/c line. I first noticed it in the attic and thought it was a leak. After further inspection, I notice it was coming from the small line. Not only do I hear it in the attic but also at the condensor outside. You can hear it whistling through the lines about every 3-5 seconds. You don't even need to get down to hear it. Just close. The big line is very cold and sweating but upstairs is not getting cold although the filter is clean and the blower has no restrictions and is blowing strong. During the night it turns off and on like its suppose to but it still seems extremly hot with the temp reading around 70degrees now. The temp today was 84 and the unit has not turned off I'm figuring sense this afternoon. Had to go to work. Its now reading 71 with the stat set on 68 and a temp outside of 79 with no sun. Although the stat says 71, it feels like its in the 80's and I even swapped stats with downstairs which is set on 68 and now its reading 68 so now thermostat problems. Yes, its cold downstairs..... The outside unit is 2 months old (Goodman 3 Ton) and the inside is a (ruud 2.5) which is about 7 years old with a piston size 65 which the tech said was OK. I also check the coils and they where not dirty. Any suggestions??????? THANKS
 
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  #2  
Old 09-26-07, 05:13 PM
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Clean the outside coil. Sounds like you aren't getting a solid liquid line.
 
  #3  
Old 09-26-07, 07:15 PM
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outside unit is new. no dirt, branches, grass or leaves.
 
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Old 09-27-07, 05:46 AM
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I'd still clean it. A layer of dust is almost impossible to see, but will still effect heat transfer. As long as the suction line is sweating/cold, the unit is probably fine. You don't have a TXV so that can't be the problem. You have two thermostats, do you have two complete systems, or is this a zoned system?
 
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Old 09-27-07, 06:59 PM
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Call the installer back and have the system gauged.

Also have the blower speed checked; airflow in excess of 400-450cfm per ton can reduce dehumidification.

You should be comfortable at 75F+; 68 is a really low setpoint.
 
  #6  
Old 10-08-07, 01:57 PM
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Great news. A/c is working fine now. I had a friend who came by to check my a/c last week. He said the filter was dirty which caused the condensor unit lines to freeze up outside. When I changed the filter, I didn't give the unit enough time to defrost before calling the installer back which said the unit just needed a little refridgerant. Actually, it didn't need any. It gave him a bad reading and he really overcharged the system causing it to blow warm air again after two days. My friend came by and did a pressure test and said he was getting an extremly high reading between 95-105. He recovered a good portion of refrigerant and my problem was solved in 15 minutes at no charge. Now my wife and kids are complainting about its too cold set at 76. Thanks to all and this site for great info...... A 3 month filter really doesn't last 3 months. He says he change his 3 month filter every 2 months. I had no idea a filter play a big part with the condensor unit. "What you learn to know now may keep you from spending big bucks when you don't need to".
 
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Old 10-08-07, 02:09 PM
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Wink

We try and tell people to get a new filter every 30 to 90 days. ( I see you said KIDS----- new filter every 30 days for sure. heat and cool.
 
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