AC filter was replaced (1PM) and afternoon temperatures exceeded 83 degrees (target temp). Afternoon temperatures climbed despite the AC being on 5 hours straight (4-9PM).

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Ice was observed at 10PM and fan was engaged to de-ice.

Indoor air entering coil was measured at 79 degrees and 72 at the duct: a delta of 7 degrees. Upstairs started at 85 degrees and half an hour later was at 83.5 degrees.


I believe that the difference temperature delta should be more than 7 degrees: what is the acceptable range for the delta?

I believe that I removed all the ice (1 hour of fan treatment) however, I am turning off the AC and turning on the fan to ensure that all ice is removed. Is there anything else I should be doing to prevent \ remove ice?

More data /observations:

enter image description here

  • 1
    If your system is iceing up it may be low on freon. It would be best to get the system checked out and recharged if needed prior to damage to the system. – Ed Beal Jul 19 '16 at 12:16
  • [youtube.com/watch?v=c4i6_Xi5si4] Inspection of the liquid-line revealed that it was not cold to the touch. The video indicates that systems with refridgerant (freon) are always cold to the touch. Video does not indicate any conclusions to be drawn from a warm liquid-line – gatorback Jul 19 '16 at 16:23
  • 1
    The conclusion with a warm suction line is the same with Icing of the evaporator coil. Low Freon charge. It is possible the THV (throttle valve that regulates the temp could be stuck or a plugged orifice / capillary tube these do get plugged or damaged on occasion. I would look at the charge level first. – Ed Beal Jul 19 '16 at 18:54
  • 2 pounds of R22 added to the system and the temperature delta is 15 degrees – gatorback Jul 20 '16 at 2:53
  • Sounds like progress hope they measured the temps and filled it up correctly. I also hope they checked for leaks. But at least you are getting more cooling, iceing may stop now. – Ed Beal Jul 21 '16 at 0:22

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