sewer smell in house

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It's typical that the AC unit condensate line include a trap at the unit but none-the-less the line should not terminate in a sanitary line.
In fact, it is common that there are two lines coming out of the AC unit. The normal condensate line and an overflow line.
Remember that those AC traps do not see condensate all year round and are subject to drying out. They typically don't get equipped with trap primers, so legal or not, you must ensure that the trap always have a water seal.

EDIT: Don't lose sight of the fact that those condensate traps are not approved plumbing traps.
 
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It's typical that the AC unit condensate line include a trap at the unit but none-the-less the line should not terminate in a sanitary line.
In fact, it is common that there are two lines coming out of the AC unit. The normal condensate line and an overflow line.
Remember that those AC traps do not see condensate all year round and are subject to drying out. They typically don't get equipped with trap primers, so legal or not, you must ensure that the trap always have a water seal.

EDIT: Don't lose sight of the fact that those condensate traps are not approved plumbing traps.

They are approved by the international mechanical code
the plumbing code does not deal with hvac
chapter 3
 
Frodo, is there one place that is better than another to install the Ptrap? I ordered one today. Hoping it arrives soon. I was thinking it should be installed closest to where the two lines from the HVAC enter the main condensate line.
 

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yes. install it there

How often do you use that sink where the line AC line drains to?
I also see something else connected to that drain via a cross
how often is tht used.
reason i ask
It looks like......
those two fixtures are draininging into a floor drain or hub drain
I get that feeling due to the concrete cap around the base of the pipe.
 
Frodo,

the utility sink sees frequent use. Most every day.

opposite the utility sink drain, there is a rough-in for plumbing for a washing machine. See picture.
There is a floor drain not too far from the HVAV. But, my concern with draining the condensate line to it is the floor would get wet, and pose a slip hazard. You can see the HVAC in relation to my floor drain.
 

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Maybe the floor drain trap is dry? Add a bit of water and see if the smell goes away.

trap is full. The smell is coming from the condensate line. As soon as i sniff where the condensate line enters the hvac unit, I smell it.
 
Pour some vinegar into the condensate line. As a note, my condensate line clogged up and flooded two rooms of my house. I called my insurance company for help, and they advised this was a maintenance issue and was not covered by my homeowner's insurance.
 
Thanks for the tip! However, the smell is clearly coming from the sewer. Vinegar won’t do much I’m afraid.
I either need to use the PTrap system Frodo shared, or re-route the condensate line to my floor drain.
 
@frodo, is there anything I can do in the interim to eliminate the sewage smell coming from the condensate line? Remove it from the unit and plug the line? AC isn’t running, and likely won’t run for a few months.
 
They are approved by the international mechanical code
the plumbing code does not deal with hvac
chapter 3
Exactly! They are not an approved trap by size and in this case would not comply to the required vent that would be required under the plumbing code.
 
The furnace likely creates water discharge all year, even in winter.
If you have a humidifier, that creates waste water.
Modern furnaces create condensate when they burn gas, since the heat is recovered from the exhaust and that moisture no longer goes up the chimney.
 
If it is a combination furnace/AC unit it's still not suppose to be hard piped into a sanitary line.
I don't think even the Mechanical Code allows that.o_O
 
the rules for condensate drainage were vague for years. officially they are supposed to be above the trap. It looks like the plumber knew what he was doing. If you cut in a 3/4 trap on the drip line the smell will disappear. its a $2 fix unless you dont have the glue. im not sure the hvac code even requires primer.
 
Well here is the condensate trap. I located it downstream of where the lines come out of the unit about 2 ft. It was as close as I could get in such a confined working space. I used pvc glue and some silicone tape for added insurance against leaks.
The pitch is about 2.50° which is a bit shallow. But seems to be enough to allow the condensate to flow. I allowed the trap to slowly fill, and witnessed the water flow through the trap and downstream.
So hoping and praying this resolves my stinky smells. Thanks to everyone for their help. Special thanks to Frodo for putting me on to this piece of equipment.
 

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