# sewr gas smell



## bkplumber (Jan 24, 2011)

Ok guys i need to pick your brains. I have a job that the home owner is smelling a smell. It smells like sewer to me. It only happends when they run washer and kitchen sink. They said its been going on for over a year. So, they had a 1 1/2 tubular p-trap on washer, i thought maybe its sucking dry. We changed it out to a 2 in p-trap and changed vent. Still smells! Today we did q smoke test on sewer lines and foud nothing. Has anyone else had this problem?


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## RealLivePlumber (Jun 22, 2008)

They left a turkey on the floor next to the freezer, about a year ago.


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## waldrop (Dec 18, 2009)

Do they have a island sink ?


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## Airgap (Dec 18, 2008)

I tend to fart alot when I have to do the dishes or the laundry....Might be a long shot though.....


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## Plumberman (Jul 7, 2008)

House on a slab or elevated?


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## Plumberman (Jul 7, 2008)

Scratch that question, just re read and said y'all did a smoke test...


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## 422 plumber (Jul 31, 2008)

Could be a trap siphoning out, a 1.5" tubular trap for w ashing machine is a clue that there is bad plumbing involved. The k.s. might not be vented.


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## 3KP (Jun 19, 2008)

1.5 p- trap(PVC , copper, or ABS) is code in the upc code book. I don't hink tubular is though. I always try to go with 2" but sometimes you have to go what's given to you. 

back to the smell... Ummm I shoot you straight I have no clue !

Well again it could be a dead critter in the wall, Is the laundry and kitchen close? The original plumber could of put he wye to close and it's sucking the trap out at the kitchen when it's passing by?? 

GOOD LUCK! I hate these calls..:furious:


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## Redwood (Sep 8, 2008)

Tell us how you did the smoke test.


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## rocksteady (Oct 8, 2008)

bkplumber said:


> So, they had a 1 1/2 tubular p-trap on washer, i thought maybe its sucking dry. We changed it out to a 2 in p-trap and changed vent. Still smells!


 
When you say you changed the vent do you mean you replaced 1 1/2" with 2"? Or do you mean you replaced a AAV with another AAV?






Paul


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## bkplumber (Jan 24, 2011)

waldrop said:


> Do they have a island sink ?


No island sink


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## bkplumber (Jan 24, 2011)

Redwood said:


> Tell us how you did the smoke test.


Capped all vent with rubber caps, then pulled toilet. We screwed a plug into toilet flange


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## bkplumber (Jan 24, 2011)

3KP said:


> 1.5 p- trap(PVC , copper, or ABS) is code in the upc code book. I don't hink tubular is though. I always try to go with 2" but sometimes you have to go what's given to you.
> 
> back to the smell... Ummm I shoot you straight I have no clue !
> 
> ...


We thought about the critter thing but it only smells when they run sink or washer


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## Redwood (Sep 8, 2008)

bkplumber said:


> Capped all vent with rubber caps, then pulled toilet. We screwed a plug into toilet flange


Then what? Throw a smoke bomb in the pipe and plug it?


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## bkplumber (Jan 24, 2011)

rocksteady said:


> When you say you changed the vent do you mean you replaced 1 1/2" with 2"? Or do you mean you replaced a AAV with another AAV?
> 
> Paul


The old vent was 1 1/2 in copper i changed it to 1 1/2 in pvc. We thought maybe there was a nail hole or something in vent


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## bkplumber (Jan 24, 2011)

Redwood said:


> Then what? Throw a smoke bomb in the pipe and plug it?


Yea


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## Redwood (Sep 8, 2008)

One of the things you want to do when smoke testing is to generate a slight positive pressure on the DWV System. This is just enough to force the smoke out of anywhere it can leak such as crack in cast iron, leaking wax rings, dry traps, or any other opening, but not with so much pressure that it will push through traps.

After inspecting closely and eliminating any obvious possible leaks such as loose toilet, handyman forgot a trap, dry floor drain trap, etc. you should run the smoke test.


Put a test ball in the sewer line where it leaves the house or, in the pipe at the inlet of the septic tank.

If the home has a housetrap put a test ball in the trap vent.

Cap or, plug all roof vents except one.

With one man on the roof operating the smoke machine, and another (at least 1) inside.

Use a smoke machine to blow the smoke into the remaining uncapped roof vent in a manner that generates a positive pressure on the DWV system.

The person(s) inside observe all areas inside for smoke and locate where it comes from calling the smoke machine operator to stop when the smoke source is located.

Remove all test balls, caps, and plugs, after the test is concluded.

Plbgbiz posted this link a while ago for a homemade smoke machine, looks like a great tool at an inexpensive price to me. http://www.upfrontprice.com/galleryimg/smoker_intro.htm

A fan off an old power vent water heater might be a good fan for a homebuilt smoke machine as well.


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## bkplumber (Jan 24, 2011)

Ive never done a smoke test. I just did what the tools at the supply house told me. This little fartting house job is realy getting to me. I hate when I cant figure out something. Thanks for the info.


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## macp&h (Oct 20, 2008)

Here is my 2c, did you smell the water, make sure your not smelling sulpher.


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## plbgbiz (Aug 27, 2010)

Red is on track with the positive pressure. And it doesn't take very much. In fact, it might be easy to get too much. You want the leak to show but slow enough to find before you get gassed out.

I've done the drop a bomb version with no results. When I followed up with the fan...POOF there it was.

I've always felt that tracking down sewer gas leaks is one of the more difficult tasks in plumbing service.

I had one that according to my super keen sense of smell was DEFINITELY sewer gas. After 4 fan assisted bombs...no leak. Narrowed the smell down to the master bath. And it only smelled when they used the shower. Must be the sewer right?

Squirrel in the wall.


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## LEAD INGOT (Jul 15, 2009)

I had a similar problem on a remodel I did a while back. But all the plumbing was new, tested, and inspected. Turned out to be the washer itself. Weak pump, not displacing all the drain water and building a bad smell over time. They got a new washer, problem solved.


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## bkplumber (Jan 24, 2011)

macp&h said:


> Here is my 2c, did you smell the water, make sure your not smelling sulpher.


Yes we checked the water.


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## bkplumber (Jan 24, 2011)

plbgbiz said:


> Red is on track with the positive pressure. And it doesn't take very much. In fact, it might be easy to get too much. You want the leak to show but slow enough to find before you get gassed out.
> 
> I've done the drop a bomb version with no results. When I followed up with the fan...POOF there it was.
> 
> ...


You would think that a dead critter would smell all the time.


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## Plumberman (Jul 7, 2008)

Sounds like a broken sewer line or vent stack somewhere. Cast iron?


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## U666A (Dec 11, 2010)

LEAD INGOT said:


> I had a similar problem on a remodel I did a while back. But all the plumbing was new, tested, and inspected. Turned out to be the washer itself. Weak pump, not displacing all the drain water and building a bad smell over time. They got a new washer, problem solved.


Eureka! A sparkie at work was asking a couple of us about his clothes smelling lime sh/t I told him to take some pictures and sure enough, standpipe was connected downstream of the laundry tray trap. He had his father come over and they handy-hacked it up according to a half assed sketch that somebody drew and weeks later, stench is still present. Nobody on our job lives near him nor is anyone really interested in a side job, so as far as I know, problem is still there.

How did you deduce that it was a weak pump causing the water to go stagnant LI?

Sent from my iPhone using PlumbingZone


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## bkplumber (Jan 24, 2011)

Plumberman said:


> Sounds like a broken sewer line or vent stack somewhere. Cast iron?


Yea cast iron with copper vents


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## LEAD INGOT (Jul 15, 2009)

U.A.til.I.die said:


> Eureka! A sparkie at work was asking a couple of us about his clothes smelling lime sh/t I told him to take some pictures and sure enough, standpipe was connected downstream of the laundry tray trap. He had his father come over and they handy-hacked it up according to a half assed sketch that somebody drew and weeks later, stench is still present. Nobody on our job lives near him nor is anyone really interested in a side job, so as far as I know, problem is still there.
> 
> How did you deduce that it was a weak pump causing the water to go stagnant LI?
> 
> Sent from my iPhone using PlumbingZone


 I knew the plumbing was sound, it was new, tested and inspected. The washer was old, and this house is on a working ranch. Their clothes get covered in horse, cow, and barn cat scat. Has to be tough on a washer. I just had an appliance guy come over to verify my suspicions. He agreed, said it happens on older machines that get used hard.


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## Plumberman (Jul 7, 2008)

I'll go back to my original question. Since it obvious that the smoke test wasn't done exactly right. Is the house off the ground?

I ask because I had a call few years back on a bad smell in house when dishwasher was in use. My boss said it was the anode on the WH. I told him it couldn't be if it was only showing up in the kitchen. Long story short the branch line catching kitchen was broken right down from where it turned up to catch kitchen sink drain. 

As far as why it only does it when appliances are in use. My best guess is because of the hot water mixing with standing water in the pipe. I know it sounds absurd, but I have a jet tub in my master bath. It's an older model tub with floor jets. So whenever we take showers the water just pools up in the jets. 

The stagnant water turns to a black ooze looking algae and smells like death when hot water hits it. When straight cold is run it doesn't smell at all. That's why I am in the process of remodeling my bathroom this summer, too much up keep on the jet tub.

But it very well could be the same type situation here. Or even a vent cracked in the wall close to these appliances.


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## RealLivePlumber (Jun 22, 2008)

I had one in a doctors office ( his personal office, in the office bldg) years ago. Bad sewer odor smell. iIntermitent problem. I was there a couple of times for it, couldn't find anything. No plumbing in the walls. They were ready to tear out walls. I asked for permission for complete and unimpeded access to EVERYTHING. I opened doors, drawers, looked in every nook and cranny. Turns out the flourescent lamp on his desk had a plastic lens on it, and when it was turned on, after it warmed up, it smelled like the worst septic tank you ever smelled. (He even paid the bill)

That turkey I spoke of earlier, yep, it happened. 

Also had one in an office bldg basement. It stunk awful. I couln't find anything, told em I'd come back later in the week. The next morning, when they arrived, they said it was so bad you couldn't work in the bldg. They actually called the fire dept. Turns out a battery in the burglar alarm box was melting. 

Just cause it smells like shiot, don't mean it is.


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## bkplumber (Jan 24, 2011)

RealLivePlumber said:


> I had one in a doctors office ( his personal office, in the office bldg) years ago. Bad sewer odor smell. iIntermitent problem. I was there a couple of times for it, couldn't find anything. No plumbing in the walls. They were ready to tear out walls. I asked for permission for complete and unimpeded access to EVERYTHING. I opened doors, drawers, looked in every nook and cranny. Turns out the flourescent lamp on his desk had a plastic lens on it, and when it was turned on, after it warmed up, it smelled like the worst septic tank you ever smelled. (He even paid the bill)
> 
> That turkey I spoke of earlier, yep, it happened.
> 
> ...


Good point


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## U666A (Dec 11, 2010)

Duplicate post


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