A/C condensation drain installation


Old 04-18-05, 07:36 AM
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A/C condensation drain installation


I'm in the process of buying a house that had an extra A/C heating system installed in a remodeling job. The A/C contractor plumbed the A/C condensation drain into a sewer vent in the attic. My home inspector marked this as needing repair since it could lead to sewer gas venting into the unit if the p-trap on the line dries up (like in the winter when the heat is in use). The A/C contractor said this was a normal installation and that the city inspected it and okayed it so it is fine. How are these installed normally in new construction? I was told that normally they should be installed on the ptrap side of a sink, but I've never seen this in any other house I've owned. Can I have it drain to the outside into a french drain instead? Any suggestions on the course of action to take. I have to either negotiate this with the seller or take care of it myself after I close. I'm almost positive that when I had a new system installed in an older house that they took the drain line to the outside and down into the ground into a french drain.

Old 04-18-05, 09:26 AM
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Your idea is exactly what I like to see. The main condensate drain going to the ground and the emergency drain dumping out over a door way or window so that you know when there's a problem.

Is the furnace a 90+ high eff or is it a conventional 80% ?? If it's a high efficiency furnace they condense during heating and that may be why they didn't run it to the outdoors.
Old 04-18-05, 10:14 AM
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Well, I talked to a couple of folks including the home inspector I used and they said that the french drain for the cities around here require a variance since code specifies to plumb it to the sewer. The original installation should have plumbed it correctly, but since the sheetrock work was already done, they took a shortcut and the city inspector probably missed it. His suggestion was to put a PVC valve in the line and close it in the winter when the heat was in use to ensure sewer gas is not pulled into the system and open it when the A/C is in use which will always ensure that water is in the ptrap. It's an electric heater, and he said it will actually draw air from the vent so, condensation is not an issue with the heater. This sounds like the route I will go since it sounds like a big ordeal to have the line put in correctly which will involve tearing out the sheetrock. Thanks for the reply. Of course, I'm open too any other suggestions. I was also told about a trap primer, but that sounds like it would be just as difficult to plumb as the drain line itself.

Old 04-18-05, 11:25 AM
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Im with Matt here after you are in the home Id just run it to the outside and down on the ground. Still have a P trap in the line by the unit. We dont use any french drain, just let it on the ground. The overflow or catch pan run it out over a door or window so you can see it.Im sorry if they say go into the vent with it. Code here sure dont and never has. With it tied to a vent stack of the home you could still get methane gas, valves or not. In the unit and that can KILL

my .02 cents

Old 04-18-05, 05:00 PM
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Drain into vent

Putting the condensate drain into a plumbing vent is specificly outlawed in every code I've ever seen. I'm with the other guys here. Once you are in the house, do as you darned well please. I've seen them run into rain gutters, just barely sticking out the soffit, etc. But most importantly get it out of that vent. The local code people are dead wrong except it won't be them who could be dead. It could be you.
Old 04-20-05, 02:31 PM
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To kd5dea

I had my ac connected too the septic vent with no p-trap for 2years and I had septic smell in the house and I could figure it out until one day I was looking in my owner manual for the furnace and notice the figure of a p-trap so I put a new tread on this forum and I learn that this gas is toxic .

Since that time I removed everything and redid the installation the right way

I install the ¾ “drain pipe from the safety pan too the outside right beside the back door so my family and I could monitor any sign of over fill.

I did some rechearche and found this wonderful waterless p-trap ezt 150 from www.eztrap.com
And install a ¾’’ drain pipe from the p-trap too the gutter with a small screen at the end.
I also install on the secondary drain a float switch from ez trap ezt 224 on the outside no need too go inside too check it out .this is a wonderful product.

Since that time I never add any smell and if for any reason my p-trap fail I don’t worry about it because it is not install on the septic vent. I sleep safe at night.

I want too thank very much this forum for making my family and I safe at night with your expertise.

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