# Dual Water Heater System troubleshoot



## 6stringmason (May 20, 2005)

We have a dual Water heater system. Both 50 gallon.

I had to replace one of them after the gas company red tagged it because the lp controller valve was junk. 

So I put the new (used 5 year old) tank in, filled it, but didnt have the materials on hand to hook the exhaust up properly. 

Went home, came back a few days later and got everything hooked up and lit. 

Well, now when I feel the cold in from both tanks they're both just as hot as the hot water out pipes are, and the showers only give hot water. The sinks and toilets all use cold water fine. Any ideas?


----------



## 6stringmason (May 20, 2005)

BTW, all the showers in the house are only able to get hot water.


----------



## griz (Nov 26, 2009)

Mixing/Tempering shower valves?


----------



## 6stringmason (May 20, 2005)

Not sure? They're older. They mount to the wall and your have one handle to control the water temperature. I assume thats mixing.


----------



## KillerToiletSpider (May 27, 2007)

Parallel or series?

With or without return?

Was the replacement an exact match to to the existing?


----------



## 6stringmason (May 20, 2005)

I will take a pic of it and post next time Im up there. I've got no idea about those questions.


----------



## 6stringmason (May 20, 2005)

Ok, Im baaacckkk! I have a picture of the system I found on my computer. I hope it shows enough.

The tank on the right was replaced with a 50 gallon Bradford White water heater. Now, when I light that one, and it heats up, the cold in gets hot, and we cant get any cold water out of the showers, only hot, hot water because I keep the water temps a little high on the heaters.

Any ideas why this would be? The Bradford is a little bit shorter than the one on the left, by about 5 or 6"


----------



## KillerToiletSpider (May 27, 2007)

The system is piped in parallel, if the heaters themselves are not identical it is going to create an uneven draw when the hot water is turned on. If you want to use dissimilar heaters you need to pipe them in series as opposed to parallel.


----------



## 6stringmason (May 20, 2005)

Would an inline temp sensor stopper thingamabob be alright to put in as opposed to getting two new water heaters?


----------



## KillerToiletSpider (May 27, 2007)

You don't need two new heaters, just repipe the ones you have in series.


----------



## Rio (Oct 13, 2009)

6stringmason said:


> Would an inline temp sensor stopper thingamabob be alright to put in as opposed to getting two new water heaters?


Do what KTS is suggesting (putting them in series) and it should take care of your problem. 

You do this by taking the cold water in to the cold water inlet for the water heater, then take the hot water out from that tank and run that to the cold water in to the other water heater.


----------



## Oconomowoc (Oct 13, 2011)

The current system is completely out if balance. You won't fix it in a parallel configuration. 

Although manufacturers don't recommend hooking water heaters up in a series configuration at this point it's your best option. 

Be sure to set the temperatures correctly on both units so they are "worked" equally.


----------

