# Smoke test help



## gear junkie (Jun 20, 2008)

Looking to make a smoker. Got the materials today after seeing Randall hilton's blog. Never done this before. 

Do all the vents need to be capped off? Can I put the smoker on any cleanout? Any other tips or methods on the procedure would be appreciated.

So here's the situation. Bar and grill. Smell has been there for the past 4 years and I'll be the 6th plumber to look at it. Grease trap right out the back door and gets jetted every 6 months. This is where the smell was the strongest, right by the back door. Standing outside(where the grease trap) and you can't smell a thing. Walk inside...whew...knocks you back. The smell comes and goes and goes at random. I smelled it today and it was definently grease smell. The HVAC system isn't zoned but the fresh air intake is on the roof. The fart fan exhausts close to the grease trap area but the bathrrom inside had no smell. By the back door is a newly installed mop sink and vent but the smell was present before. Essentially all the drain lines have been replaced in an effort to find the fix but no one ever did the smoke test.


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## eddiecalder (Jul 15, 2008)

Are there any Fan coils or HRVs? I had one building that had an trap on a HRV unit in the ceiling that had dried up. The HRV was circulating sewer gas throughout the building. Lots of plumbers (4 i think were thee before me ). 

I would not cap the vents until you can see the smoke coming out of them. I would also smoke check the fart fans (hopefully there are ceiling tiles)

You should double check all floordrains just to be safe. 

Good luck.


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## eddiecalder (Jul 15, 2008)

Dont run any water before the test to make sure its not just a trap that s not primed.


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## TX MECH PLUMBER (May 27, 2011)

Ok. I did a test on a control tower at an airport that we built. It was about 140 maybe to the top of the stack on the roof and there was a one story building attached I got smoke at all vent terminations I don't know what your smoker is but I set the smoke bomb on a piece of metal and slid it in the pipe and then used a fan... It was a small Stanley fan black and yellow that we took some flex duct and taped it to the fan really good I used the fan to push the smoke up the pipes and closed each vent as I got smoke from it starting with the one closest to the smoker I then went up 8 floors to the top of cab and with one more smoke bomb I got smoke !! Capped it and use the fan to put a "pressure test on the dwv". If you have a strong blower and rig it tight maybe in a 4" mip and screw in a co. Ect ect. U get the point. Fill with smoke !!! Then seal the system shut Then add pressure maybe just a few in. W.C. But its enough to force out the smoke


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## TX MECH PLUMBER (May 27, 2011)

In ur case I would turn off all fans air hndlers ex fans fan coil. Ect ect. Remove all aspects of it you can. Then kick on the equipment as you test if you don't find any thing when it's all calm!! If you test long you might open a cap and check you smoke once in a while to and pump some more in if needed. When testing in a ground co we cut a rod or pipe long enough to go into the ground co but short enough that you can put the co plug back in We wire the smoke bomb to the rod cuz the wire won't melt or burn of course.( duct tape doesn't work for every thing) light it drop it in and plug it when ready


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## Redwood (Sep 8, 2008)

you need to put a test ball on the outlet to the main sewer line to block it.

Plug all openings except the one that you are blowing the smoke into. You want to be able to build a positive pressure on the DWV system.

I would also highly recommend the smoke machine be outside the building. You'll understand once you start the smoke blowing...

I'd also recommend having someone outside running the machine and having a sufficient number of people inside to be able to observe all areas where smoke may come out of... It sure beats starting it up and going inside to wonder where the hell did all that smoke come from...:laughing:

Set up the blower pressure first making sure that you aren't hitting it too hard and have it blowing through the traps...

I guess thats about it...


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## stupid helper (Sep 30, 2012)

We had a situation once And a store was getting sewer smell back in the building.. Well come to find out they had gotten a new A/C unit installed and there was a vent stubbed up out of the roof about a foot from it.. It was drawing the sewer gases back in through the unit.. I might be way off subject but its just an idea

best helper minimum wage can buy


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## smoldrn (Oct 4, 2010)

stupid helper said:


> We had a situation once And a store was getting sewer smell back in the building.. Well come to find out they had gotten a new A/C unit installed and there was a vent stubbed up out of the roof about a foot from it.. It was drawing the sewer gases back in through the unit.. I might be way off subject but its just an idea
> 
> best helper minimum wage can buy


Had one this summer where the smell only showed up in the late afternoon. There were 2 studor vents for the bathrooms that we replaced, the odor came back. When one of the help said the odor was worse by the front door,(where there was no plumbing), I finally located the air handler. They had ran the pan drain across the building & tied it into a vent. Duh uh.


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## gear junkie (Jun 20, 2008)

Thanks everyone. Lots of good info on this. Test is scheduled for tomorrow. I'll post how it goes.


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## ChrisConnor (Dec 31, 2009)

Wire your blower up with a dimmer switch to control the cfms. 

I go for an outside cleanout or roof vent when I do them, but have connected under a sink with a fernco when that wasn't available. I don't used the dryer exhaust hose that Randall has on his unit, but a two inch shop vac hose. It doesn't fit in the toolbox like Mr. Hilton's, but allows seal versatility.


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## SewerRatz (Apr 25, 2009)

The way I did it for the building I was ha ing issues with was hooked up my smoke machine to the vent on the roof. Did not need to block off the sewer outlet or anything special. 

We found our first leak in the drip ceiling, an open tee, seemed like they forgot to plumb in a cleanout. Then we fired the smoker again and found smoke coming out of a wall by a cooler. When the installed the walk in cooler they cut a line and left the ends open. 

Point is after you find a leak and fix it, smoke the line again.


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## gear junkie (Jun 20, 2008)

Thanks on the dimmer idea Chris. I bought a 19" kobalt toolbox to hold it but it doesn't fit. Went to HD and bought the homer 19" and it fits great.


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## Cuda (Mar 16, 2009)

gear junkie said:


> Thanks on the dimmer idea Chris. I bought a 19" kobalt toolbox to hold it but it doesn't fit. Went to HD and bought the homer 19" and it fits great.



Buy cheap, buy twice.
Sorry Ben I had to lol


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## TX MECH PLUMBER (May 27, 2011)

Where can I see a pic or info on this machine y'all are talkin about ?? Does it make smoke?? Or just help insert it in the system ?? Thanks


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## DesertOkie (Jul 15, 2011)

If you cap all the vents, don't use to much pressure. It can blow the water out of lav sinks. Gets nasty stuff all over the mirrors. I prefer going from the vent but that was on 1 or 2 story houses.


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## 89plumbum (May 14, 2011)

I would also be conscientious of the floor as you know older pipes could be improperly capped below tile/carpet.


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## gear junkie (Jun 20, 2008)

I'll take pics but right by the mop sink is an exposed vent with a cleanout cap. I was planning on attaching right there. 

Desert okie, how much pressure are we talking about? It's just a bathroom fan for the blower.


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## gear junkie (Jun 20, 2008)

TX MECH PLUMBER said:


> Where can I see a pic or info on this machine y'all are talkin about ?? Does it make smoke?? Or just help insert it in the system ?? Thanks


http://www.upfrontprice.com/galleryimg/smoker_intro.htm

Mine is almost exactly the same but I used industrial grade blue duct tape instead of the black as recommended in the link.


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## Redwood (Sep 8, 2008)

gear junkie said:


> I'll take pics but right by the mop sink is an exposed vent with a cleanout cap. I was planning on attaching right there.
> 
> Desert okie, how much pressure are we talking about? It's just a bathroom fan for the blower.


Make sure the smoke bomb is outside...

Run the fan and adjust the pressure so that it isn't bubbling through the traps before lighting the smoke bomb...


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## Gettinit (May 9, 2012)

gear junkie said:


> I'll take pics but right by the mop sink is an exposed vent with a cleanout cap. I was planning on attaching right there.
> 
> Desert okie, how much pressure are we talking about? It's just a bathroom fan for the blower.


I have always used a leaf blower on low and never had a problem so those little fart fans shouldn't be a concern. All you really want is to see smoke coming out of all the vents. With eyes below, one 30 second bomb should be plenty but I would buy at least 10 at a time. 

Call the fire department before hand.


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## TX MECH PLUMBER (May 27, 2011)

Thanks


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## gear junkie (Jun 20, 2008)

Here are some pics.


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## Gettinit (May 9, 2012)

So, tiled over floor drain? Clean out plug installed backwards because they were too lazy to get a recessed plug?


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## gear junkie (Jun 20, 2008)

Pic 1. Grease trap by the back door. During the test, smoke was just gushing out the thing. At first the wind was blowing the smoke away but at the end of my time there, the smoke was coming into the building.

Pic 2. The 2 vents are what I believe for the grease trap, smoke was coming out of here as well and you can see the bottom of the vent in the 1st pic by the door.

Pic 3. The first test was done through the c/o above the mop sink. Had absolutley no smoke inside the building.

Pic 4. 2nd testing done on dishwasher line because it supposedly was seperately vented then everything else....however no smoke out of any vents. Seemed as if the vent was capped off in the ceiling. No smoke in ceiling space.

Pic 5. just ignore pic 5, the vent comes up into the ceiling on the right side of the sprayer directly above the whole ceiling tiles.

Also discovered that the owner has a door with no weatherstripping on the bottom of the door and the only one with a grease trap out the back door...only one with a grease trap as well. Talked to the manufactor and they confirmed that no smoke is supposed to out of the grease trap. I'll be there Tuesday morning to replace/fix the gasket.

My theory is the fumes from the grease trap is getting sucked into the kitchen because of negative pressure from the exhaust and is staying there because it's such a smaller area. Thanks Mark and Richard for your help on this.


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## gear junkie (Jun 20, 2008)

Gettinit said:


> So, tiled over floor drain? Clean out plug installed backwards because they were too lazy to get a recessed plug?


We looked, turned off all the lights and searched everywhere. Trust me, this frustrated the heck out of me. I'm used to being able to positively say "this is the problem and I can fix it"....instead it was "this is a problem and let's try this solution".


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