central AC drainage problem

Page 1 of 2  

I get a bad smell in my hallway near the AC unit when I run the faucet in the kitchen. I've posted about it on this group before and have gotten suggestions that it's a problem with the vent pipe.
I bring the plumber in and it takes a while but I finally convince him about the smell (of course the few times I've gotten them in the smell doesn't appear), and he tells me that it's possible that the AC drain line leads into the sewage lines; but it's illegal for it to do it. So he says what they can do is open up the walls and run a line to the outside of the building and let it drain through that. It looks like they'll have to open up a sizeable chunk of wall to do that unfortunately
Before I commit to the time, expense, frustration, and risk that this will cause I wanted to see if anyone saw any other solutions? I mean, I guess it needs to drain but is there any other way to do that?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 27 Oct 2006 13:24:24 -0700, snipped-for-privacy@hotmail.com wrote:

Open up the AC unit, and stick a cork in the drain for a few months to see if that fixes the problem, first.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Goedjn wrote:

I don't think that's an option, I'm in South Florida and the AC runs all year and creates a lot of drainage. The line became clogged a few weeks ago and I had to empty out the drain pan manually twice a day or it started overflowing.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com wrote:

Did you smell sewage while the line was clogged? I suspect you did not...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Carpenter wrote:

Actually I did, I don't think the pipe was completely clogged, just mostly. I can't remember precisely but I think it was even worse.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Does it smell like sewer gas? I am concerned because the faucet in the kitchen should not affect this (as you said, the sanitary sewer connection would not be legal ... but illegal does not mean that it did not happen).
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Charles Schuler wrote:

Yes, it's definitely a sewer smell.
Well a theory that I've heard and which I kind of agree with is that running the water in the kitchen causes some sort of pressure change that pulls water out of the p-trap off the AC drain pan. It's not only when the kitchen faucet runs; it sometimes happens spontaneously, and I'm guessing that the water in the trap has evaporated enough to let gas in.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

OK, just some basics assuming your AC drain is connected to the sanitary sewer:
1/ It might not have a trap. 2/ When fluid is being pushed into the sewer pipe there will be a pressure change. 3/ Trapped gas can then flow backwards, due to the pressure change. 4/ You get to "enjoy" the smell of the sewer gas as it is pushed back into the evaporator unit of the AC. 5/ The sewer gas can also get back there under other circumstances.
I think the AC condensation need to be re-routed!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com wrote in

Make a trap in it like a sink
http://i14.tinypic.com/4cadqbm.jpg
Mine definitely goes outside but have a trap. Keep in mind during the off season the water in the trap can evaporate and it will once again be clear to where ever it goes.
Maybe use the cork idea in the off season? Or put a shutoff valve for the off season REMEMBERING to open it before using the ac.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You should contact Air Over Texas http://www.airovertexas.com . They really are exceptional when it comes to residential HVAC. If commercial HVAC is what you need then try ACIS http://www.acisinc.net
Regards
On Oct 27, 3:24 pm, snipped-for-privacy@hotmail.com wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That's going to be a large charge for mileage to South Florida...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Illegal? Why on earth would that be?
The condensate from the A/C is about the purest water one can find.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That's the reason. City services doesn't like treating water that doesn't need treating. It adds to the expense for treatment, and isn't billable since sewer fees are charged based on water usage. For the same reason it's illegal to hook up a sump-pump to the sanitary sewer.
-Tim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Oh.
Of course they don't mind charging sewage treatment fees for water used on the lawn or for washing the cat.
Probably the same bastards who object to putting lawn clippings and used motor oil in the storm drains, I'll bet. I always maintained the drains needed "roughage" and occasional "mineral oil supplements" to function properly.
In a city in my neighborhood, a chap drilled a water well in his backyard, just for horticultural purposes. City had a shit hemorrhage when they found out!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Because it causes the problem OP is experiencing... Air conditioners don't reliably keep a trap filled, and therefore allow sewer gas into the building.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Oh. Mine dumps into the sewer via a trap then into the stack pipe.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
They make ac drainage pumps so you are not dependent on gravity when deciding the best route for the drain.
Where is the central ac unit?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Art has the right idea-- use a condensate pump. They are made specifically for this purpose, relatively inexpensive (about $50) about the size of a shoebox or smaller, and have a builtin safety switch that should be wired into the a/c to cut it off if anything happens to the pump. The outlet is run in 3/8 copper tubing to wherever you want it to terminate. It is NOT illegal to drain a/c condensate into the sewer, and in fact in some places it is code to do so. It is just illegal to hook it up as yours is. A lot of the newer houses here have the drain tied into a branch tailpiece under the bathroom sink if the unit is in the attic or uptairs. Good luck Larry
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com wrote:

I would seek a second opinion. If I read your note correctly this plumber doesn't know for sure that the AC is draining into the sewage line. Unless you blind folded him, he should have been able to tell. IMO.
Can you put a large container on the floor near the AC? Before tearing down walls I would try routing the AC drain temporarily to that container (can't be too tall) and see if the odor goes away.
If that works you could consider starting your own pure water company...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Carpenter wrote:

Well there's a pipe leading from the AC drain pan that just runs into the wall; he said that there was no way to tell from looking unless he opened up the wall. I just can't think of any other explanation for the smell, it's strongest directly under the drain pan when it comes.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.