Condensation drain line question


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Old 07-01-20, 08:43 AM
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Condensation drain line question

Good morning,

i have a unit in my attic and Iím not seeing any water come out the drain line. I went and checked and there is a little water in the pan...not much, but some. When I poured some water down the main drain line, it did come out of the pipe outside the house, however I noticed that the secondary line would put water back up in to the pan when I mildly suctioned it with my finger. Should this be happening? Should water ever be in this pan and trapped in the secondary line? Here are some pictures for reference. My thinking is all water should exit the house via the primary line, maybe Iím wrong?


 
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Old 07-01-20, 09:48 AM
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In your main drain the area that clogs most often is the trap. If you were pouring water into the fitting on the left you have not verified that the trap is clear.

I don't understand the bit about suctioning with your finger on the secondary line. Since it isn't normally used I almost never find the secondary clogged unless an insect has built a nest inside.
 
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Old 07-01-20, 10:04 AM
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How would I go about checking to see if the trap is clogged? Yea, I am not sure what to make of the secondary line. So I poured water in the main line and it did come out the pipe outside, however, when I mildly suctioned the secondary line at the pan opening, water came back up to the pan which was strange to me....I wouldn't think water should be in that line...and even if it made it to that line, it should clear out and not stand in there, correct? For my setup up, should the pan ever have water in it, or does that indicate there is a problem somewhere in the main line?
 

Last edited by sguarrera; 07-01-20 at 11:42 AM.
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Old 07-01-20, 01:57 PM
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I use a looong zip tie. They are sold for use on ductwork but you can use anything long and flexible; small plastic tubing, semi flexible wire... If you want to buy something look in the plumbing department for a zip drain cleaner. Stick it in the open fitting aimed toward the trap and run your tool in and out and see what you fish out. Even if it's clogged almost any tool will go through. Clogs are often more like snot so if you bring back mucus on your tool just keep working it around to break everything up.

 
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Old 07-01-20, 08:17 PM
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There should not be any water in the overflow pan. If there is it means the primary drain is plugged. There should be a float switch installed in the secondary port to alert you when the main drain is plugged. The secondary drain is always slightly higher in the unit then the primary drain.

I use the float switch in the link below. It screws into the secondary port. You can wire it into the A/C system to shut it down on overflow. You can also pull the switch out of the fitting to pour in hot water and bleach. The typical clog is just inside the pan where the drains connect. The bleach will clean that and go down the drain.



Float switch
 
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Old 07-02-20, 04:35 AM
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You have to cap that tee. When the blower comes on it will pull a suction and not let condensate flow out that primary line. Many techs make that mistake.But

Some coil manufacturers specify NO trap on a positive pressure application, If your equipment is in a conditioned space, the air escaping from the vent won't be a great loss.
Drains on a negative pressure location must have a trap or the water will not drain.
 
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Old 07-06-20, 08:15 AM
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Thanks everyone. I appreciate the responses
 
 

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