I need help figuring out what my AC is doing

[ultrarunner]

My little portable air tank has cleared many a condensate line here at work... one building has 14 package units and one large built-up unit...

Keeping the drain lines free flowing is part of the job and a shot of air is just the ticket 99% of the time.

Keep some heavy gauge weed wacker line on hand to rod it out too... works great for sunroof drains.

 

[dodge man]

When my plugged up I used air to blow it out also. Mine is just a tube that dumps into a floor drain. I get that maybe its not plugged up but maybe its plugged up enough that its not draining as well as it should?

 

[EddieWalker]

You have to have a deep trap on the condensate line when the coil is before the fan, that prevents air being sucked back through the drain line, without it no water will drain. Seems that the negative pressure has increased past what the trap can hold. Check everything in the return air side of the system including the evap coil.

Thanks, this explains what's happening. When I have the drain pipe off, I'm sucking air in through the 3/4 threaded opening that is stopping the water from flowing out. Now I'm thinking that my trap might not be deep enough, and the air was being sucked back through the pipe, also causing the water not to drain, but instead, be lifted out of the tray.

I'm going to make my trap bigger!!!

Thank you.

 

[coolreinfarm]

A deeper trap may help but not cure the problem, if the system has been in operation for a few years with no problems then something has changed. You noted that you run the a/c 10 months out the year, I would suspect something is clogged on the return side, you also said this is located in the garage, it could have a fire damper in the return and supply ducts that has closed or partially closed, here in the north those dampers are required by code, I don't know in your part of the country. Just a thought I had I've only serviced this stuff for 45 years now retired thank god.

 

[EddieWalker]

Well, I might have forgot to mention that I relocated the drain when I created my second kitchen for my wife to process her veggies. I moved the drain, which I never had any issues with, to this new location. I also created a new trap that is fairly shallow. Now I'm thinking it was barely deep enough to actually be a trap.

 

[coolreinfarm]

Well that explains a lot, a deep trap should correct your problem, FYI fill the trap prior to starting the a/c.

 

[jaxs]

Retired after decades of refrigeration tells me that collectively,the answer is in above comments combined. The wet filter act's like dampers that was spoke of in post #14. Following advice in post #16 is important. Locate trap 6" to 12" below pan so that trap has some head pressure. The opening where you have been adding bleach, temporarly cover/plug it to prevent air being sucked in.

 

[EddieWalker]

It seems that the water issue is all my own doing. When I relocated the drain line, I didn't realize how important the trap was, or that if it isn't s deep enough, the fan from the AC will pull air in through that line and stop the water from draining. It all makes sense to me know. Thank you. Here is what it looks like with a much deeper trap.

 

[ultrarunner]

Have a lot of traps and the vertical is always open to atmosphere... think roof vent for a drain line so no cap.

Also found that the PVC traps flow better than site built with 90 elbows... but even then they still will clogged if left for a year or so...

 

[jaxs]

That will certainly overcome the problem but may create a new one. The trap will be pron to stopping up because there's too little difference in level of pan and line out of trap. To maintain some head as mentioned earlier, I would like to have seen the line leaving trap about where that clamp is. The short pipe with cap is the secoundary drain and should have a line on it as well. It's a good idea to place secoundary so that it catch's attention when it drips. Mine come's out of soffit above window over kitchen sink. In rental property,I normally route secoundary to drip where tenant stand's to shower.