I've just recently noticed that warm air is coming out of my bathroom sink every time I have the heater on. I'm not sure if it's something I can remedy myself or if it's something I have to call a plumber for. I've also noticed a foul odor coming out of the sink every time the warm air comes out of it. The bathroom is located on the second floor and the house is only a year old.



Thanks in advance.

Is the heating vent right under sink? Does the vent have a leak and its coming out by your sink? The reason I ask is in some new houses the vent is right under the vanity or sink.

Hi Jack,

Nope, the vent is no where near the sink. It's weird though since I have a side-by-side sink in the master bathroom, my sink is the one acting up and the one right next to is OK... no odor or air coming out of it whatsoever.

No air comes out unless heat on? Forced air heat or boiler, hot water?

It's a forced air heat and I have no problems with the hot water either and the air no air won't come out unless the heat is on. I messed around with my thermostat and found out that air is also coming out of my sink when I turn on the AC.

Some how a vent line is blowing air into your pipes or into the wall behind the vanity? Which doesn't make sense? That's my guess.Where is your heating vent in the bathroom located,in coralation to sink? Do you have a vanity or sink on pedestal. Sorry so many questions I'm just trying to make heads or tails of it?

Sounds like your p-trap is absent or leaking out. The heat/ac cold air returns are causing the vacuum that is pulling the sewer gas in.

http://www.vandykes.com/images/products/02000543-lg.jpg

The heating vent is located on the celing, several feet away from the sink. I've also noticed the first night I've spent in the house, I've turned the heater on and a weird clanging noise was coming from behind the mirror, located near the problem sink. The noise went away after a day or so. I'm sorry if I'm horrible at describing my master bath to you, but I don't have a pedestal, it's kind of like how your generic kitchen counter is: Sink, counter, and the bathroom mirror right on the wall.

So does that mean maybe he can tighten the connections on this and it might correct the problem?

I wonder if the heating vents run behind the wall that the mirror is on and sink I'm drawing straws but I'm trying to think on this one, I don't think its your plumbing but its hard to say for sure without being there and why just one side of sink and not the other?

Is the p-trap present under the sink or not (see above) ? Is it leaking? Does the problem still occur after you just ran water in the sink?

Almost be willing to bet,
1. That your furnace is in the attic,
2. That the AC condensation drain is piped into the vent.

Quote:

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I've just recently noticed that warm air is coming out of my bathroom sink every time I have the heater on.

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OK! I guess we can discount the hot air vent being coinected to the lavatory drain. Is the warm air being forced out or is it a gentile whiff of warm air the comes out of da drain? Bad smell? Just like Jack Dandy I'm going to go out in left field and speculate the air vent's touching the lavatory drain and is warming the air in the drain by convection. Since warm air raises the air in the drain will just drift out into the outside. Of course all this is so much garbage if the air coming oiutta da drain is being forced out like a hot air vent. Let me know! Tom

I think hkstroud pointed out a very possible solution!

Hkstroud, yep my furnace is in the attic. So... does this mean I have to call a plumber or an ac/heating person to fix the issue?

If you don’t understand the answers about components to look for causing this like a p-trap and ac drain line. It is best to call a professional. A plumber is your best bet and be sure to explain the problem and show him as you did here. Also mention the fact your attic furnace may be draining into your plumbing.

The drain for AC condensation comes off your plenum or A-coil box with an approximately 1” line. Along with the water draining a small amount of pressurized air whether ac/heat is running does blow through this pipe. Depending on where this is tied in, the least resistance for the air could be coming up through your sink instead of venting up the soil stack.

The heater/ ac has a 1" line coming out near the top to carry away condensation during the summer when the A/C is being used. This line should empty into a floor drain or to the outside. I don't believe that it is permissable to connect it to the plumbing system but it is sometimes done. This line should also have a small trap built into it to trap water, sealing the unit from blowing out air or insects entering. Either you do not have any water in trap because you have not used the A/C or the fan has blown it out. If you have the trap and can connivently open the line (some have a clean out plug) pour some water into the pipe. You can cut the line along a vertical run, add some water then reconnect the line with a coupling. If the bottem line below the cut is supported, just glue the coupling to the bottem section of the pipe and stick the top section into the coupling without glue. This will make a convient place to clear the line should it become blocked (it happens). It won't leak. If this does not solve the problem the fan is blowing the water out. If you don't have a trap install one. You can purchase one, which is only a bent shaped piece of PVC or you can make you own. Cut the pipe at a connivent place along a horizontal run, add a 90 degree elbow, pipe down 4-6", add another elbow go 4-6" horizontally, another elbow come back up to pipe and connect with another elbow. If you already have a trap but the fan is blowing the water out construct one as described. The fan should not be able to blow the water out of one that deep.

If you have a 90% efficiency furnace go to this posting in heating and A/C

Condensation line freezing in NC, codes and recommendations ?