# I dunno



## Tankless (Jun 12, 2008)

Two tanked heaters in an attic (standing room). They are set in smitty pans (round). Both drains are tee'd together than ran (in copper) to the exterior. I am bidding a tankless retrofit. 2 units - now, in an attic install I still need to have the catch pans there, but do I need to seperate the drain lines and run them independantly. I understand completely the requirements for the pressure relief discharge lines, but ai'm not sure on these. Anyone know?


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## service guy (Jun 26, 2008)

The way I was told is that the pan drains should be going to an indirect waste drain, and the t&p relief lines also should be going to an indirect waste.

So you could have both pan drains and both relief tubes all going to ONE indirect waste drain which should then drain to the outside.


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## service guy (Jun 26, 2008)

The north carolina continuing education instructor told me this less than a month ago, new code update.


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## RealLivePlumber (Jun 22, 2008)

When we install steam generators (for shower stalls), we fabricate a pan, and have to drain it indirectly into a 2" pipe. 

Our code says if a unit is installed where it can cause damage to the building, it must have a pan under it.


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## Tankless (Jun 12, 2008)

service guy said:


> The way I was told is that the pan drains should be going to an indirect waste drain, and the t&p relief lines also should be going to an indirect waste.
> 
> So you could have both pan drains and both relief tubes all going to ONE indirect waste drain which should then drain to the outside.


 
Hmmm, I know this, I cannot reduce the size of the pressure relief (no temp on tankless systems) I cannot have a tee on the line, I cannot have a valve on the line.

This attic install is on the second story, about 20-25' above the grade is where the stub outs would happen, than about 6 90's worth of turns to run down the exterior wall to the grade. There are rain gutters and crap in the way so it will be difficult to say the least. I also need to run an 1 1/4" gas line UP that wall too. The only way I think it might work would be to run an indirect in CPVC, but knowing I cannot reduce the size of the pressure relief, that's now 1 1/5" CPVC...and sorry but that's ghetto and I am not saving anything. I have priced it for 4 runs....1 pan drain - 2 pressure reliefs and one gas line....I am just second guessing the pan drain....I seem to remember something about not reducing from the 1" port on the side wall of the pans.....these are tee's together in 3/4"

Does the pan drain need to terminate like the pressure reliefs do? 6 - 22" above the grade? If not I could in effect terminate the pans near the top of the house...like the HVAC guys do with their pan lines.....hmmmm


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## RealLivePlumber (Jun 22, 2008)

Tankless said:


> Two tanked heaters in an attic (standing room). They are set in smitty pans (round). Both drains are tee'd together than ran (in copper) to the exterior. I am bidding a tankless retrofit. 2 units - now, in an attic install I still need to have the catch pans there, but do I need to seperate the drain lines and run them independantly. I understand completely the requirements for the pressure relief discharge lines, but ai'm not sure on these. Anyone know?


 Oh, now I understand the question. 

I would add up the aggregate cross sectional area of all of the discharge pipes, and size the indirect drain accordingly. Should be in your codebook.


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## service guy (Jun 26, 2008)

> 2009 IPC 504.7.2
> 
> Pan drain termination.
> The pan drain shall extend *fullsize* and terminate over a suitably located indirect waste receptor or floor drain or extend to the exterior of the building and terminate not less than 6 inches and not more than 24 inches above the adjacent surface.


If you have TWO pan drains, then you have to either do them separately to the outside or do them separately to one indirect waste drain.
The relief tubes should also separately discharge to an indirect drain.


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## service guy (Jun 26, 2008)

The indirect drain should be sized to accomadate the DFUs, I am not sure what the DFUs are for a water heater, but I think a 1.5" drain should be sufficient.


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## Tankless (Jun 12, 2008)

Ok, I see what you guys are saying. That would make sense with basement installations. I think I can get away with this idea. Have my tin knocker make me a pan (just one) to my dimentions, and terminate that pan at the top of the first story of the home. My heaters will be about 3" apart from eachother, and I would have two round pans under each one....doesn't make a whole lot of sense and I really would like to avoid having to run more pipe than I absolutly have to.....This is a 5K house with a boat on their dock that is worth more than my house. ALL and I mean ALL the walls in every inch of the home are custom painted, so simply opening up certain areas was out of the question. They also want a cover for the piping but on the water everything rusts...even stainless steel.....Hence my other thread about a vynal pipe cover. I'm starting to think 10 grand is a deal....for them


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## service guy (Jun 26, 2008)

Whatever you do, the drain or discharges will have to terminate between 6" and 24" above grade.


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## TheMaster (Jun 12, 2009)

Yeah have a custom pan made with a 1.5 copper female adapter soldered in. Take the 1.5" pvc out and down to the acceptable temination above grade. Aluminum doesn't rust so you could have a custom cover built out of aluminum. I used a pvc gutter over some water pipes a week or so ago. I'm not that proud of it but the owners didn't wanna spend the extra 125.00 to have a custom cover built. So it is what it is,I mainly used it as a shield from the wind and to protect the insulation from the sun.


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## RealLivePlumber (Jun 22, 2008)

service guy said:


> The indirect drain should be sized to accomadate the DFUs, I am not sure what the DFUs are for a water heater, but I think a 1.5" drain should be sufficient.


 We don't have a dfu for a water heater. We have a chart in the codebook. We must use a 2" indirect drain for a 3/4" wh relief valve. Also can not terminate a relief valve into a drip pan. 

I would pipe the 3/4" relief valves outside, seperatley, and the 1 inch drip pan, also seperate. Just stub them out the wall, up high. Of course, I would ask the local inspector first, then draw a very detailed plan and submit it for code review. If it is approved, pipe it like the drawing. If we do it that way, the inspectors are usually pretty good about working with you. 

On a side note, we had a big discussion in a license continuing ed class. Guys were *****ing drip pan drains being 3/4" or 1", saying that they were too small. Instructor said "hey it's a drip pan, not a catastrophy pan":laughing:


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## TheMaster (Jun 12, 2009)

RealLivePlumber said:


> We don't have a dfu for a water heater. We have a chart in the codebook. We must use a 2" indirect drain for a 3/4" wh relief valve. Also can not terminate a relief valve into a drip pan.
> 
> I would pipe the 3/4" relief valves outside, seperatley, and the 1 inch drip pan, also seperate. Just stub them out the wall, up high. Of course, I would ask the local inspector first, then draw a very detailed plan and submit it for code review. If it is approved, pipe it like the drawing. If we do it that way, the inspectors are usually pretty good about working with you.
> 
> On a side note, we had a big discussion in a license continuing ed class. Guys were *****ing drip pan drains being 3/4" or 1", saying that they were too small. Instructor said "hey it's a drip pan, not a catastrophy pan":laughing:


 We hafta use a 1.5" drain if it also serves the relief valve. if its just the pan the minimum size is 1". Most people use 1.5" here now.


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## Protech (Sep 22, 2008)

How do you connect the 1.5" to the pan?


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## TheMaster (Jun 12, 2009)

Protech said:


> How do you connect the 1.5" to the pan?


 You connect the 1.5" to the fittings that attaches to the pan. All factory


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## Protech (Sep 22, 2008)

I have never are you using a large commercial pan or something? I've never seen a pan with 1.5" drain fittings on it that was for resi. I've seen that on a big 32" pan for commercial heaters a few times though.


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## Tankless (Jun 12, 2008)

I wonder if there needs to be a certian min. cu/in for two tankless units.....Which may impact the discharge pipe size. I know I am overthinking it at this point and well, we just don't have that smart of inspectors in this area....


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## Protech (Sep 22, 2008)

I know what you mean. I did a remodel in the city of Winter Haven once and the inspector walks up to a hammer arrestor and says <completely straight face> "OK, I see you remembered your studor vent, good." 

Me: <fighting desperately to keep a straight face and be cool> "Yeah, I remembered."





Tankless said:


> I wonder if there needs to be a certian min. cu/in for two tankless units.....Which may impact the discharge pipe size. I know I am overthinking it at this point and well, we just don't have that smart of inspectors in this area....


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## TheMaster (Jun 12, 2009)

Protech said:


> I have never are you using a large commercial pan or something? I've never seen a pan with 1.5" drain fittings on it that was for resi. I've seen that on a big 32" pan for commercial heaters a few times though.


 I'll take a pic of it for you. Its just a residental aluminum pan. They make them for all size pans.


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## TheMaster (Jun 12, 2009)




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## smellslike$tome (Jun 16, 2008)

Don't know if this would be allowed but as a variance you might check and see if they would allow the use of a scupper. If yes then just use an indirect large enough to accomodate everything which then leads to the scupper. This would leave a much nicer finished look on the exterior.


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## donchange (Feb 27, 2009)

*pan*

Pan


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## Protech (Sep 22, 2008)

Where do you get those TM?


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## TheMaster (Jun 12, 2009)

Protech said:


> Where do you get those TM?


 Local supply houses. A few years ago a hughes supply shut down here and I got a couple cases of them. I still see them in the supply house along with the 1" style. The one i posted the pic of will accept either 1.5' or 1" pvc.


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## jeffreyplumber (Dec 7, 2009)

*smitty pan required*

Heres my opinion , If memory sereves right. Tand p must be piped to the outside or an approved location (basicaly outside or floor sink) not into the pan. they should definatly not be tied together. As for the pans It would seem they should be seperate but when you think of it its kind of an emergency drain. only one will be needed at a time. An emergency floor drain in a restroom counts as zero fixture units you could run 100 of them on a 2 inch line. so I gues you can use your pans as they are. Not sure but it would make sence. But hell plumbing code isnt supposed to make sence is it?


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## PlumberLakeElsi (Mar 23, 2010)

great post very informative....


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