My AC says it is trying to cool to 73 but is reading 75. I changed the filter, which didn't help. I looked in the closet, and apparently the installers were supposed to install an "auxiliary shut off switch to a/c condensation line to prevent water damage in case of main drain failure." I have water condensation dripping down a long white PVC pipe and water collecting on top of the unit. What is going on with my AC?

Picture 1 shows condensation and the top is just spewing cool air. Condensation

Picture 2 is the whole unit. enter image description here

Picture 3 is condensation. enter image description here

Picture 4 is condensation running down the PVC pipe to the floor of the closet. enter image description here

Picture 5 is water pooling on top of the unit where there is green. enter image description here

  • 3
    Cold pipes in a humid climate are going to have condensation on the outside.
    – Michael Karas
    Commented Jul 16, 2020 at 21:39
  • 2
    That piece of pipe with wires coming out of it, that says "safety switch" is your aux shutoff switch. It has a float in there, such that if the bottom vertical piece gets clogged, that will shut off the output before it can overflow the top vertical piece above the T.
    – Nate S.
    Commented Jul 16, 2020 at 21:44
  • If you look down the open end of the top pipe, do you see standing water pooled in there?
    – Nate S.
    Commented Jul 16, 2020 at 21:45
  • It looks to me like the condensate drain line is constructed properly and is equipped with a cut-off switch. Also, I don't understand what you mean by "says it is trying to cool to 73 but is reading 75"; you have a setpoint, which is the temp you have set the unit to cool to; you have a room temperature reading, which is just a thermometer. Are you saying it will not cool the area to the desired setpoint? If it won't, then it needs servicing. Commented Jul 16, 2020 at 21:52
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    I do see a potential problem with the vent. That vent pipe is likely supposed to be a "B-Type" vent (double-walled) and the straight pipe is but I don't think that adjustable elbow coming from the top of the unit is. Commented Jul 16, 2020 at 21:59

1 Answer 1


I believe you may have a charge related problem. When ac systems start having icing issues they stop effective cooling a low charge can cause ice to form on the evaporator high moisture in the air you see , sometimes with severe icing it takes hours for the ice to melt, the system may run ok for a short period of time then start icing up. A simple recharge can solve this very common problem , if a R22 system note the cost of this refrigerant is very high +100 per pound a 5 ton system usually has 11-13 lbs and will need 5-7 lbs in most cases.

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