Central A/C Unit not cooling (Line cool but not cold.)

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Old 07-25-15, 04:11 PM
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Exclamation Central A/C Unit not cooling (Line cool but not cold.)

I have a 30 year old (Flame Master?) unit that worked good for about 5 years but last week i turned it on and the house wasn't cooling so i went downstairs to the furnace to find that the line wasn't very cold i thought "Great now i need to have the thing recharged." The capacitor is good the unit starts up normal with the side panel removed i hear the Compressor kick in when i push the Contactor with an insulated Screwdriver. So i am beginning to think maybe its a refrigerant problem. But i came here as i have no further experience with HVAC.

Thanks

Its 30 C outside im melting!!!!
 
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Old 07-26-15, 01:41 AM
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Nathan, does the outside unit turn on by itself when the thermostat calls for cooling? You mentioned that you hear the compressor start when you manually push in on the contactor. Is that the only way you can get the outside unit to turn on? If so, you need to see if you have 24VAC present at the side terminals (thin wires) of the contactor. The contactor is a relay. When the 24VAC control signal from the house is present, the contactor pulls in and supplies power to the outside unit.

If you have a voltmeter (or are willing to buy one), see the thread below for information on how to troubleshoot the absence of 24VAC at the contactor.

http://www.doityourself.com/forum/ai...r-outside.html
 
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Old 07-26-15, 07:15 AM
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Could be as simple as an airflow problem. Install a new clean return filter. Inspect all supply registers to make sure they are not cut off or blocked by furniture etc. Inspect evaporator coil for dirt and clean if needed. Inspect condenser coil and clean as needed. Restart and see what you have and report back if any further problems. You can buy the coil cleaner at HD or Lowes. Make sure all power sources are turned off and locked out before doing any work on your equipment.
 
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Old 07-26-15, 05:25 PM
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The unit does kick in with the thermostat. I pushed the contactor in as a test.
 
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Old 07-27-15, 01:55 AM
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Have you had refrigerant added in the past? If so, did the technician locate and repair the leak? A/C systems are closed systems and ideally should never have to have refrigerant added. However, if you've had to have refrigerant added previously and the leak was never repaired, then you are likely low on refrigerant.
 
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Old 08-06-15, 02:24 PM
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No i have never had refrigerant added in the past. But i just realized after picking about 50 burrs off of my clothing that there are several weeds growing in beside the house being sucked against the unit which also made me discover that the fan is turning clockwise which i thought was the right direction. But that causes air to suck through the coils blowing hot air out the fan. Though if i remember correctly the hot air blows out through the coils. Im thinking these weeds may be the problem though.
 
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Old 08-06-15, 02:49 PM
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The condenser fan rotation should be to pull air in through the condenser coils and expel it out the top. In other words, the fan should be blowing air up & out rather than sucking air in and down.
 
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Old 08-08-15, 07:52 PM
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So is it probably the weeds screwing it up? Looks like i have to pull the ol' weed eater out?
 
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Old 08-09-15, 04:18 AM
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Yes, the condenser coils (the fins that wrap around the outside unit) need to be kept free of obstructions. You don't want to have anything closer than 6" from the outside unit, with 1 foot clearance even better.
 
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