Horrible Smell

[Aheim]

In our bathroom we are getting a very bad almost like a sewer type of smell that wafts in through the heat vent, when the heat runs no smell, and if we run the water in there the smell also goes away. Which is why were thinking it's something to do with the plumbing and not the duct system. We're going to try and see if the vent is clogged. Anyone have any suggestions or ideas?

 

[plumb_bob_square_pants]

Slab or crawl space? Single or multi story? Where is the air handler in reference to the vent?

 

[Aheim]

Its a single story home, and its on a slab. Not positive about the air handler in reference to the vent.

 

[plumb_bob_square_pants]

Well it seems like all your duct would be in the ceiling right? Well if you have a smell it would be helpful to know how far away is the air handler to rule out condensation pipe. This is a tricky one because it seems to be including your hvac system as well. Pictures always help. Take some of the vent and the bathroom and as well as the air handler itself and post them back on here.

 

[Aheim]

I am not quite sure where that is, and the ducts are in the floor. Now today the smell doesn't seem as strong, and goes away when you run water down the bathroom sink. It makes absolutely no sense!!

 

[plumb_bob_square_pants]

If you do not have a crawlspace or basement then it sounds like your ductwork is ran in or under the slab. This does not sound right to me. We do not run a lot of duct underground. It is common for swimming pool HVAC systems to have pvc duct work in the ground but I don't think I have ever seen it in residential before. What state are you in and around you able to take pictures and post them?

 

[Aheim]

We live in a manufactured home, it sits on a cement slab, and you can crawl underneath the home. If that makes sense? Smell is still there today but comes and goes still.

 

[plumb_bob_square_pants]

You have a crawlspace. There is a good chance you may have a leak in the crawlspace and some duct work that is not sealed up properly. When air is pushing through there is positive pressure and when it is off then there could be pull through the vent into your house. This is the best explication I can assume based on the information that you have given. Check your crawlspace for the same smell. That will tell you a lot..