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The Right Way To Install A Condensate Drain

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84K views 26 replies 18 participants last post by  ehang  
#1 ·
How's it going guys.

I have been seeing many different ways to run a condensate drain in my years of doing AC service.

Bottom Line: What is the right way?

I usually work with existing equipment so I haven't installed a condensate drain years.

I do some light repairs and cleaning.

I recently got involved with installing a new Horizontally Mounted Attic Air Conditioning Split System.

I hung the unit trapeze style with threaded rod and uni-strut so it's off the floor a bit and I can get some good pitch going for a condensate drain.

I used a Goliath Pan with the electronic overflow switch.

I was wondering what is the best way to do the drain.

Over the years I have seen systems with one drain coming off the primary and the auxiliary is capped off.

I've seen the primary and secondary tied in together and running out one pipe with a trap.

I've seen drains with and without vents.

I've also seen a drain going outside from the primary and then a short drain with a trap going to the auxiliary drain pan. (which seems like the auxiliary drain would suck air)

Please give me some opinions on this if you could.

Also post pictures or links if you've got them.

Thanks

Warren

Precision Appliance Repair
 
#2 ·
Condensate drains seems to be everyones way to express themselves. People think that there way is better.

When you buy a unit to install, the installation manual tells you step by step on how they want the condensate line run, Float switches are required by code for systems that have the potential to cause water damage. The Secondary drain tap should go to conspicuous area (For the customer to see there is a problem without causing damage.

There is not enough focus during training on Drain lines. For the amount of damage that it can cause there should be adequate time spent on the understanding of it all..

When I install I follow this:

Manufactures Specs
Local Code for me, its the B52 Code book
Common Sense
 
#3 ·
You need a vent tee after the P trap if the drain is on the negative side of the unit. I naturally install a vent tee on every installation I do along with a 3/4" PVC union that comes off the unit so during maintenance I do not have to cut and install a coupling while blowing out the lines. As long as you have an emergency pan under the unit, which code should call for, I usually cap off the secondary line coming out of the unit or tie into the primary line.

Out of everything I do on an install, the drain line is always the most important. Getting a call at 3 A.M. with the customer saying water is coming out of their ceiling is heart dropping.
 
#4 ·
I, for the life of me, can't understand why so many systems are installed without any way of inspecting or servicing the primary drain line or the secondary is capped off. It seems like the most basic thing you can do: install a trap that can be cleaned and purged when needed and provide a redundant method of draining water. It's that simple.

And of course, you also want to mindful of air being pulled into the supply stream. If there's no trap and you have negative pressure, air outside the unit (either outdoor, attic, or crawlspace) will be pulled, unfiltered, into the air stream.

The secondary line should run to a drain pan with a sensor. An exception to this is when it's installed in garage, in which case the secondary can empty onto the floor so the homeowner is visually alerted if the primary backs up.

And for heaven's sake; run the drain lines with a grade! Too many times I see drain lines running 10 feet flat on the floor or go up a few inches before going back down. It needs to be running downhill, continuously.
 
#5 ·
In new constuction here we run the drain to a 1 1/2" ptrap installed in a vent line by the plumbers. 3/4" traps will not pass inspection anywhere around here. I run my the over flow drain down in to the safety pan with a float switch. Don't like to cap over flow cause if drain stops up the water will over flow into insulation in unit.
 
#6 ·
I dont get too many horizontal attic jobs where I'm at but the ones I do get I will install an ss2 in the secondary drain outlet in the a/h. I suspend all my a/h's from up top with a hanging kit so I can hang the emerg. pan underneath it with a heavy pitch to one corner and install an ss3 in that corner. This way, as long as everything works as it should, the emerg. pan hopefully will never see any water. If it does, its very little in one corner. I can remember lots of times getting service calls for a unit not cooling. Find it off on the float switch in the emer. pan where it was installed level and it had several gallons of water in it that has to be removed. Ive even seen some 2 piece pans in a couple commercial jobs on large horz. a/h's where the pan collapsed because of the weight of the water because some nim didnt put enough pitch on the corner where the float was or they put the pitch at the opposite end where the float was......lol.

Normally, I will do my trap and clean-out tee at the top or inlet to the trap so water can be flushed thru it but as long as its not tied into another drain line somewhere, it can be vacc'd out or sludgesucked from outside pretty easily. I dont ever use running traps on a horz. only a P trap and will make it to my own if the specs call for one bigger than the premade ones.

Ive never been a fan of letting the secondary drain dump out somewhere but I guess that is each installers preference. I guess its better to dump out onto a floor somewhere than to fill up someones ceiling....lol.
 
#10 ·
Thanks for the replies.
I wanted to install a primary trapped drain that runs down with my line set inside of a PVC line set cover. My concern about running a short drain with a trap to my auxiliary drain pan is even though its trapped it's essentially a dry drain until their is a problem. My evap coil is on the negative air flow side of the air handler. This means that hot attic air will probably be pulled into my evaporator. Can you load the auxiliary drain trap with some kind of fluid that won't evaporate like anti freeze or some kind of oil so that it won't suck air but will be open for water if necessary?
 
#14 ·
New Drain Line Maintenance Code



This is something that should be checked out by every A/C Contractor. It is very cost effective and built with the tech in mind. http://www.youtube.com/watch?v=Zrbysv8KN8s&list=UUxZQ-5Zh6Gxc6t9SMJBlGBQ&feature=share&index=13
The IMC passed a code that is being published next month that will require a way to clear and maintain the drain line without cutting or pulling it apart. It is a "Drain Line Maintenance" Code and has passed for the IRC and IMC as well.
 
#16 ·
Your required by the IMC to use the IPC slope requirements for your drain if going to a plumbing system. Any pipe 2 1/2" or less is required to have a minimum 1/4" continuous slope in accordance with the IPC.

This will prevent your drain line from getting stopped up. If your drain line gets stopped up then use a cup of Clorox poured into the drain and that should unclogged it ASAP.

Even if not going into a plumbing system you should always have at least a 1/4" slope to keep the drain line clear. Thank you very much
 
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#17 ·
The "All Access" device looks like a genius idea. I've been using 3/4 PVC compression couplings to gain access to PVC drains. This takes the idea to a new level. Most clogs I find can be removed with a strong Wet Vac on the end of the drain outside. But I've had a few that would not budge.
 
#19 ·
Thank you! The AA1 allows you to completely service the drain using any method you like.it is built well and is very inexpensive.
It also meets the new upcoming Drain Line Maintenance Code requirements.
www.allaccessdevice.com has a list of distributors.
Code wise it will be six more years before GA and several other states adopt a new mechanical code and that should be the IMC-2018 in 2020.

Most states change every 6 years instead of every three to save on the cost of implementation. Just want to throw that in. Looks like a good device there.

You still need to have your proper slope and then hopefully you won't have any problems to worry about. Thank you, thank you very much
 
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#21 ·
Maryland is adopting the new Residential code some time in January. You are correct that states take time to update codes. The IMC Passed the code in both the Residential and Mechanical. When I introduced the SS1 and SS2 float switches years ago, nobody wanted it and it only took off because code officials saw the need and benefit of it even though it was not code yet. This product is for the Contractor and code should not play into it. It really saves time for techs and is an easy add on sale to homeowners as it gives those that want to, easy access to add any chemical or tablet that is recommended by their A/C company.
 
#22 ·
Leaking condensate line

I'm a noob and my Son has an issue with his drain line at his rental. The unit keeps dumping water on the garage floor. What I believe to be a clogged line ( I was able to blow out the line) still leaks. What I found was the last service call the repair person cracked the elbow at the top of the line.

With this kind of trap my assumption is the water is coming from the cracked elbow.

So what we were going to do was cut off the current elbow replace.

But the question I have is do I need this "U" type trap on the drain line?

I was going to replace this with a straight run with grade that will run into 2 additional elbows.

Like I said I'm a rookie at this and appreciate any comments.

Thank you.

Not sure how to post a picture but will keep trying.
 
#24 ·
I noticed this is an old thread which has been revived by someone today.

It made me think of a question - other than serving as a cleanouts do vents after the trap serve any other purpose? Do they prevent traps from aspirating due to pressure changes on the drain side just like vents for sewer systems?
 
#26 ·
The capped stub before the p-trap is the clean out, the open one after is the vent and also the second clean out.
Image


Sent from the Okie state usin Tapatalk
 
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