# TnP drain line with company



## JamesNLA (Jun 2, 2006)

Here is one I did last week. Residential retrofit and everything worked out great. My question is on the exaust drain tee, it is installed correctly including my water filled loop to seperate spent gasses above the water line. Manufactures specs say install drain tee line to local code. I can't find anything on this sort of thing. I connected the drain tee to the Tnp 3/4 L drain that runs outside. 

The pictures that the Noritz people have shown me have the lines draining to a slab floor. I'll assume in that local area, that was code. I asked 2 other plumber buddies in my area about it, and they had no clue. I guess I can wait till I see an inspector, but they usually disagree with eachother on silly stuff like this. Anyone have an idea on this?


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## mdshunk (Mar 13, 2005)

I don't think you can tee another line into the relief valve discharge. 

_*P2803.6.1 Requirements of discharge pipe.*_
_The outlet of a pressure relief valve, temperature relief valve or combination thereof, shall not be directly connected to the drainage system. The discharge from the relief valve shall be piped full size *separately* to the floor, to the outside of the building or to an indirect waste receptor located inside the building. In areas subject to freezing, the relief valve shall discharge through an air gap into an indirect waste receptor located within a heated space, or by other approved means. The discharge shall be installed in a manner that does not cause personal injury or property damage and that is readily observable by the building occupants. The discharge from a relief valve shall not be trapped. The diameter of the discharge piping shall not be less than the diameter of the relief valve outlet. The discharge pipe shall be installed so as to drain by gravity flow and shall terminate atmospherically not more than 6 inches (152 mm) above the floor. The outlet end of the discharge pipe shall not have a valve installed._

There is a proposal for the '09 revision that was approved that will further clarify that. It reads, in part:
*P2803.6.1 Requirements for discharge piping.*
_The discharge piping serving a pressure relief valve,_
_temperature relief valve or combination thereof shall:_
_1. Not be directly connected to the drainage system._
_2. Discharge through an air gap located in the same_
_room as the water heater or to the outdoors in_
_climates not subject to freezing temperatures._
_3. Not be smaller than the diameter of the outlet of_
_the valve served and shall discharge full size to_
_the air gap._
_4. *Serve a single relief device and shall not connect*_
*to piping serving any other relief device or*
*equipment.*
_5. Discharge to the floor, to an indirect waste_
_receptor, or to the outdoors. Where discharging to_
_the outdoors in areas subject to freezing,_
_discharge piping shall be first piped to an indirect_
_waste receptor through an air gap located in a_
_conditioned area._
_6. Discharge in a manner that does not cause_
_personal injury or property damage._
_7. Discharge to a termination point that is readily_
_observable by the building occupants._
_8. Not be trapped._
_9. Be installed so as to flow by gravity._
_10. Not terminate more than 6 inches (152 mm) above_
_the floor or waste receptor._
_11. Not have a threaded connection at the end of such_
_piping._
_12. *Not have valves or tee fittings.*_
_13. Be constructed of those materials listed in Section_
_P2904.5 or materials tested, rated and approved_
_for such use in accordance with ASME A112.4.1._​

I think you'd have been better off routing that exhaust drain over to a sump pit, the furnace condensate pump, a floor receptor, or someplace like that.​


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## Moscow (May 3, 2005)

First I must say very nice job, looks neat and clean. As an inspector I would allow the way you have the t&p and condensate installed. In my thinking you would have no problem with the water draing from the t&p or the condnsate. To me there is bigger fish to fry then what you have done. 

Justin


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## JamesNLA (Jun 2, 2006)

Thanks MD, that about sums it up than. I had a feeling it might be out of code, than again, I highly doubt it would fail an inspection. For commercial stuff I dare not do that, for residential most of the local inspecters are pretty lax. Now that I think about it, I really don't know why I didn't run it out with the tnp to outside. In my parts we don't usually have sump pits...for anything. Maybe the folks up in the mountains do. The furnace had no condensate line that was visable, however I did fine a 3/4 drainage line that was BELOW the newley poured slab, they left about a 1/4" of clearence which would do nothing but stop the drain up. 
Anyhow, thanks for looking that up it's appreciated.


Thanks Justin, it's always nice to hear things like that. I bust my rear off to make them as clean and simple as I can. Here's a pic of another I just finished. W/H was in a bomb shelter 8X6 room under the house, below the crawl. Originally there was 3/4 soft to the W/H in, and on the hot, was reduced to 1/2" for a 35ft run to a single bath room, which had 2 sinks - 1 bath tub - 1 shower. To me that is 4 fixtures off one 1/2" line. It was the original builder's (1950's) plumbing but I was taught that was a no no. 3 fixtures per 1/2" max. Either way I re-ran 3/4 cold and split them, 2 fixtures per 1/2" same for the hot. Which brings me to a question I have for everyone:

Why in the hell would I do a run like that in copper (given the price) when I can just redo it in PEX Pipe? There are not a whole lot of guys using pex around here but it is starting to catch on from what one of my supply houses tells me. I did the math on a proposal I just finished, and that was relocating from a bomb shelter to outside. In copper the materials was $350 - in pex it was $70. Am I missing something here?


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## mastadon (Nov 16, 2006)

JamesNLA
I'd just like to say very nice looking work. Around here there are a lot of plumbers (not all) who don't care what their work looks like. (Many don't have a license either.) It makes it really hard for Plumbers like us. Once I got the good reputation, the inspectors would walk into a house I did and know who plumbed it. Too many plumbers around here care only about the almighty dollar and not their reputation. Just nice too see someone else who does care.


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