# Multiple water heater piping arrangements



## deerslayer (Mar 29, 2012)

I have always done the traditional every pipe the same length for eqaul draw on a 2 heater system. Is there any other or better ways to pipe a multiple water heater system and still maintain an eqaul draw?


----------



## rjbphd (Feb 5, 2010)

deerslayer said:


> I have always done the traditional every pipe the same length for eqaul draw on a 2 heater system. Is there any other or better ways to pipe a multiple water heater system and still maintain an eqaul draw?


 Same way.. as you said, the better way. With the craps they make nowaday, I piped mine behind the heaters so that way when one fails, much easier unit replacment.


----------



## deerslayer (Mar 29, 2012)

rjbphd said:


> Same way.. as you said, the better way. With the craps they make nowaday, I piped mine behind the heaters so that way when one fails, much easier unit replacment.


That is another reason why i am asking when 1 heater in a multiple heater system fails they never wanna replace both so pipes can be of eqaul measurements because the new heater is always different?


----------



## 504Plumber (Jan 26, 2011)

Can run them in series and pipe one hot into the cold line, can't isolate a heater when it goes out in that case though.


----------



## deerslayer (Mar 29, 2012)

504Plumber said:


> Can run them in series and pipe one hot into the cold line, can't isolate a heater when it goes out in that case though.


If you did that wouldn't the first heater do all the work until it ran out of capacity?


----------



## mtl723 (Mar 31, 2012)

No. First u can isolate it with ball valves. Second you turn the first one down to 90 degrees and the second one to desired temp. It works.


----------



## 504Plumber (Jan 26, 2011)

deerslayer said:


> If you did that wouldn't the first heater do all the work until it ran out of capacity?


In a sense, both heaters hold full tanks of hot water, when in use the second heater gets replenished with already hot water. If you somehow manage to use up all the heated water you would still have both of them running to recover. That's usually how we run them down here and I feel that it works a lot better.


----------



## eddiecalder (Jul 15, 2008)

You could do reverse return.


----------



## SewerRatz (Apr 25, 2009)

First in last out is the best way.


----------



## TX MECH PLUMBER (May 27, 2011)

SewerRatz said:


> First in last out is the best way.


Can you explain ??


----------



## eddiecalder (Jul 15, 2008)

TX MECH PLUMBER said:


> Can you explain ??


The first tank supplied with water is the last tank that is piped to the return. This can be done with either a two or three pipe system (three pipe is better).

Type both ways into google and search images ( I dont know how to post pics).

here is a link for pics 

http://www.google.ca/search?q=rever...ct=mode&cd=2&ved=0CBEQ_AUoAQ&biw=1280&bih=515


----------



## BigDave (Mar 24, 2012)

deerslayer said:


> I have always done the traditional every pipe the same length


AND same number of turns (i.e. fittings)
No better way! IMO:yes:


----------



## eddiecalder (Jul 15, 2008)

Another example

http://www.phcnews.com/sept_09/rohrs.php


----------



## sparky (Jan 8, 2014)

stub out one cold line from the wall and one hot line,run a cold line to both heaters,and tee both hots into the hot line,easy replacement of one heater and still able to use one if other goes bad.


----------

