Water Heater Questions
#19
  Re: Water Heater Questions by MarkSLSmith (Folks,  My old wa...)
2 issues with running up hill from a relief valve. First, if it discharges and doesn't drain, there will be a column of water sitting on the valve disc that can significantly add to the point at which the valve will open next time. Second, the valve components above the disc are not noncorrosive.  If that space is allowed to sit full of water it can rust the valve shut and render it ineffective.
Blackhat
Common decency is as rare as common sense. I figure there was only a finite amount of both made and its getting shared out among too many folks.


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#20
  Re: RE: Water Heater Questions by Snipe Hunter ([quote='geek2me' pid...)
(07-12-2018, 05:06 PM)Snipe Hunter Wrote:  All I know is that PVC is waste pipe and can't handle much heat or pressure. ... If PVC pipe is inside the home, it can only be drain/waist pipe. Anything supplying water under pressure has to be CPVC or Poly (Pex) as far as plastic pipe goes. 

There must be some confusion. White plastic PVC is commonly used for cold water supply lines and meets code in that application.  The only difference with CPVC is that it can be used for hot water where the white standard PVC cannot.  PVC is not limited to DMV use, at least by code.

In the water heater relief valve application, the end of the pipe is commonly open, so there is essentially no pressure.  The question would be whether it is required to meet the hot water temperature requirements, which would require CPVC rather than just PVC.
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#21
  Re: RE: Water Heater Questions by geek2me ([quote='Snipe Hunter...)
(07-14-2018, 08:57 AM)geek2me Wrote: There must be some confusion. White plastic PVC is commonly used for cold water supply lines and meets code in that application.  The only difference with CPVC is that it can be used for hot water where the white standard PVC cannot.  PVC is not limited to DMV use, at least by code.

In the water heater relief valve application, the end of the pipe is commonly open, so there is essentially no pressure.  The question would be whether it is required to meet the hot water temperature requirements, which would require CPVC rather than just PVC.

In my area pvc can be used for supply lines such as from a water main to the house but cannot be used for distribution inside.    The discharge pipe must terminate no more the 6" or less than twice the diameter of the pipe, normally 3/4" pipe so 1.5"  , if draining into the pan it must terminate the same distances listed above from the flood level of the pan.   Roly
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#22
  Re: RE: Water Heater Questions by Roly ([quote='geek2me' pid...)
(07-14-2018, 09:52 AM)Roly Wrote: In my area pvc can be used for supply lines such as from a water main to the house but cannot be used for distribution inside.    The discharge pipe must terminate no more the 6" or less than twice the diameter of the pipe, normally 3/4" pipe so 1.5"  , if draining into the pan it must terminate the same distances listed above from the flood level of the pan.   Roly

Yes, that's code. PVC to the house but not inside the house. I have seen PVC used by home owners inside the home only once. It killed the sale of the house. The guy moved his well water treatment and water heater and used PVC for most of it. It all needed to come out including everything hided by the drop ceiling in the basement.

IRC (International Residential Code) Codes

Slope of the pipe: IRC Code 2803.6.1 "Must drain by gravity, cannot run uphill or be trapped"
 
Materials: IRC Code 2803.6.1 "Materials can be any allowed for water distribution. Only Steel, CPVC, Hard Drawn Copper or pipe listed as TPRV Drain by the UPC (Universal plumbing code).

PVC is not allowed for water distribution.

IRC 2905.4 & 5 Just looked through it, very wordy but PVC is not on the list

Geek2me said: There must be some confusion. White plastic PVC is commonly used for cold water supply lines and meets code in that application.  The only difference with CPVC is that it can be used for hot water where the white standard PVC cannot.  PVC is not limited to DMV use, at least by code.

I'd like to see that in a code book, it's not in my books.
 
"My mortgage self-identifies as a student loan."
... Kizar Sozay


Neil Summers Home Inspections
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#23
  Re: RE: Water Heater Questions by Snipe Hunter ([quote='Roly' pid='7...)
(07-14-2018, 04:53 PM)Snipe Hunter Wrote: IRC 2905.4 & 5 Just looked through it, very wordy but PVC is not on the list

Geek2me said: There must be some confusion. White plastic PVC is commonly used for cold water supply lines and meets code in that application.  The only difference with CPVC is that it can be used for hot water where the white standard PVC cannot.  PVC is not limited to DMV use, at least by code.

I'd like to see that in a code book, it's not in my books.

It may be listed in a way that is not obvious to someone who is not a plumber or it may be a recent code change.  I don't have a current code book, but the one I have does list NSF certified schedule 40 PVC for cold water distribution within a residence.  I am guessing it is still to code since there are new home builders in this area still using it, but I'll have to find a copy of the current code to check and be able to point out where it says it is OK.
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#24
  Re: Water Heater Questions by MarkSLSmith (Folks,  My old wa...)
While I admit I know nothing about code....I have water heaters both at home and at work and they have been dealt with differently, see below.

At the office it is a small electric water heater with the required temperature and pressure valve that is aimed at the pan that is beneath the heater. The heater is in the ceiling and is accessable since it is a drop ceiling.  In the pan the plummer added a device called a Floodstop.  The sensor is in the pan and it goes to an alarm box just below the ceiling tiles.  If the sensor senses moisture it sets off an alarm and also closes the solenoid on the incoming water pipe.  Our maximum spill would be about 5 gallons.  They are assuming that the elements will pop their breakers when the water level drops.

At home, we also have a T&P valve also within 6" or so of the pan. The pan has an elbow on it that runs to a floor drain.  We recently had the heater replaced and the plummer told us we now need a Watts 210 gas shut off valve which takes the place of the T&P valve.  From what I have seen  this valve doesn't have an ability to release the pressure.....it just shuts off the gas.  I'm more inclined to add the Floodstop.  I have not heard of anyone that had a temperature runaway situation but we all have had a heater leak.

BTW the Watts 210  is slightly under $300 from Ferguson, pluss install they said they were just under $600.

It's a 40 gallon heater and this is some serious change   Uhoh
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#25
  Re: Water Heater Questions by MarkSLSmith (Folks,  My old wa...)
Ask them for a black and white copy of the code stating that requirement.
Blackhat
Common decency is as rare as common sense. I figure there was only a finite amount of both made and its getting shared out among too many folks.


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#26
  Re: Water Heater Questions by MarkSLSmith (Folks,  My old wa...)
(07-17-2018, 06:47 PM)blackhat Wrote: Ask them for a black and white copy of the code stating that requirement.

+1 on what Blackhat said. A gas water heater (or any other appliance) requires a gas valve but I've got nothing saying it needs to be automatic. Maybe a local code?

This isn't code (because home inspectors are not code inspectors) but it is the curriculum used for the  for states that require passing the national standard test to obtain a home inspector's license. Maryland requires passing the national standard test. But here's a link  

Water Heaters
 
"My mortgage self-identifies as a student loan."
... Kizar Sozay


Neil Summers Home Inspections
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