Trane coil box leaking

jballard81

relatively seasoned DIY'er here. Please forgive me if i don't use the correct HVAC terminology

Original Trane 1995 HVAC. XE 80 gas furnace with an encased coil airhandler connected to it. located in my attic. XE1000 outdoor unit.

My problem is with the condensate lines. the air handler is horizontally mounted w/ 2 condensate lines. the primary has a p-trap. both the primary and secondary lines are mounted very close to each other at the same level. at the opposite end from the condensate lines, the air handler is leaking.

The primary and secondary lines both terminate outside of my house. the primary isn't draining at all. I thought it may be clogged and hooked up a 6hp wet/dry vac and let it run for 5 minutes. nothing. i turned the vac back on and got into the attic and can hear air traveling through the lines no problem. i even drilled a small hole into the top of the primary line and fished around in it and found no blockage.

the secondary line is draining of course, but it doesn't seem to be able to keep up with the amount of condensate.

The air handler appears to be sealed, without an access panel that i can see at least. if my primary line isn't clogged, why isn't it draining?? could the coils themselves be so dirty that they are redirecting condensate flow away from the primary pan? could the air handler have shifted so that condensate isn't flowing towards the drain lines?

on a side note, when the AC is on, i feel pressurized cool air coming out of the primary condensate line.

Thank you for any help! i will try to get some pictures of my setup as well..

jballard81

another bit of info. We have lived in this home for 7 years, however, as i have come to learn more about the house as i fix things, the previous owners didn't do any kind of maintenance. when i moved in, the first thing i did was change the air filters, and i am betting that the PO's had never done so as they were filthy/black.

that leads me back to the hypothesis that the coils are dirty and somehow re-directing water flow away from the primary drain... i guess i will go up and try and pull off the access panel to take a look.

any advice or tips would be greatly appreciated.

Doc Holliday

Remove the doors of the box coil and see for yourself. Yes, dirt can block the (main) drain outlets from the inside BUT I have a feeling the p-trap itself has build up in it, common problem.

Go to The Home Depot and buy some 3/4" pvc couplings and a pvc cutter and some pvc cement (glue). Cut the drains open and you'll see.

Another thing you can buy and install is a 3/4" pvc "T". Install it just before the p-trap so that one side sticks up in the air. This means you'll be cutting the drain line before the trap, closer to the coil. You can use that as a blow out for later use. You may actually have to buy another trap ( on your system a trap is NOT mandatory, traps are used when an evaporator coil is located BEFORE the blower to fight the negative pull on the condensate drains, usually on one piece air handler applications with the blower located after the evaporator) but is not a bad thing to have. Also buy you a 3/4" pvc cap to plug that blow out of the new "T" if you go that route. Don't glue the cap.

again, my bet is the trap and the inside of the coil where there is a drain pan, clogged. also a yes, clean the coils as needed.

__________________
Thanks.

jballard81

OK, so there are these flexible metal "straps" about 1.5" wide that are screwed into the coil box, that i believe USED to hold the condensate lines in place. they are screwed into the only possible access panel i see on the unit. i pulled the model# this AM: txc030c4hpb1

It also looks like one of these "straps" on each side is screwed into the framing of the house. appears that this is all that is holding the coil box up. can i remove the one on the side with the access panel so that i can get the access panel off? I have been searching for some install literature for the coil box and am struggling to find how it is intended to be mounted or any other helpful tips to access.

jballard81

So i found some installation paperwork from 1995 and in the horizontal position, I incorrectly assumed that the P-trapped line was primary. it is not. I am going to try and clear the newly found primary (using a shop vac) and will report back. I still need some help on access and if it is safe to remove the strap from the access panel to get access.

Will take a picture of the access panel and maybe you can give me some advice...

Doc Holliday

If there's room under the coil you can set bricks or 2 x 4's or anything that can support the weight of the coil and then remove any and all the straps.

It's common to hang an entire system or to rest it on something such as bricks or stryafoam blocks, wood, etc.

__________________
Thanks.

Doc Holliday

If you have a shop vac that blows as well as vacuums then try to blow through the drain. I'd still cut it a few feet from the evaporator and blow through from that point, both ways. Use a towel to hold the end of the vac to the line for best results. Also, if you cut the line you're going to need at least one coupling and some pvc glue.

You are not going to find anything about how to actually mount the coil in any manual. It may state how to connect it to the furnace and to the plenum but not how to mount the entire thing as it relates to being hung up or sitting on blocks.

__________________
Thanks.

jballard81

the panel looks to be really tough to remove. i would have to bend back some of the connecting duct??

Doc Holliday

So much for bricks!

You can try removing one strap at a time and moving it over to the duct work on either side of the coil. I'd make certain there is still a strap or two connected to the back of the coil to support it's weight.

Yes, yours appears to be a difficult one. Instead of removing the doors I'd cut the drain lines near the coil and unscrew each fitting that threads into the coil and at the least take a look/clear out the drains that way. Either keep enough pvc so you can reconnect with couplings (making sure to use pvc cement/glue) or you can simply buy all the pvc fittings including new threaded 90's which are currently coming out of your evaporator and even the pvc pipe itself from The Home Depot and re-run brand new drains. There needs to be a slope of 1/4" per every 10' for it to drain, without any dips in the line.

Btw, your main drain needs to be insulated.

Pretty certain your coil would need cleaning if a bunch of dirt and grime comes out of the drain but you may need to spend the money and have an hvac contractor take care of that.

__________________
Thanks.

jballard81

great thanks! I will cut and rebuild the lines. not only is it a pain to access, you cant see from the picture, but it is situated directly over the opening to my attic. so i am straddling the opening whenever i am working on it....

hvactech126

use a union instead of a coupling when you put it back together so that it can be access more easily in the future. Good routine maintenance is to clear the drain lines every year before the cooling season.

__________________
IT IS WHAT IT IS
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

jballard81

OK, so i have removed my condensate lines, and i see standing water in the cabinet, but not enough to go over the 'ledge' of the cabinet into the condensate line. can someone give me a tip on what i can use to fish around in the pan to try to find or clear the blockage? no block was evident upon removal of the lines and from what i could see with a flashlight into the cabinet...