Is This A Parallel Configuration for two water heaters?

[Andrwatln]

Hello,

I recently had two brand new, identical, 50 gal electric water heaters installed in my house. Everything seems to be working properly, but the way the pipes are setup looks wrong to me. Can anyone confirm?

From what I've read, everything about the two heaters needs to be identical, including the length and size of the cold pipes running in and the hot pipes running out, the fittings, etc. Here is a correct configuration from waterheatertimer.org.

The way my heaters were installed resembles that of the cold water line in this diagram, except that my hot water line is installed the same way that the cold is shown below.

From what I've read, it's critical that both the cold and hot water lines meet at a midpoint like the first two diagrams, and then you must have equal lengths of pipe from the midpoint to the first fitting, and then the same length of pipe again to the water heater.

Can anyone confirm whether or not my system is configured correctly to have equal draw from both heaters? Photos of my setup are attached.

 

[Bannerman]

Since it seems the hot water plumbing from your two WH are actually combined to supply hot water to all faucets in your home, the current piping configuration will likely result in unbalanced flow between the two WHs.

By equalizing the cold pipe length both entering each WH, and the pipe distance exiting each WH before they are combined, is a method to ensure the flow rate through each WH will be as equal as possible.

To answer the question in the thread title, your combined hot water output from each WH makes your installation a parallel configuration. Water will flow in parallel through both WHs at the same time.

If each WH is plumbed to supply separate areas as shown in the lower drawing, water will not be flowing in parallel.

 

[Sponsor]

 

[Reach4]

Your setup seems like it should be pretty much intrinsically balanced with a simpler arrangement than in the illustrations. I like the looks of the method in yours. If the input favors flow to one on the cold side, it favors flow from the hot on the other.

Your photos show parallel arrangement. It seems to me that you could partially close one of the valves if there is unbalanced flow problem in the future. I don't see predictable unbalance.

 

[Jadnashua]

Regardless of how things are connected, there will likely be some imbalance in the flow between the two devices. It may be small, but it will exist. Personally, I'd think a series connection might provide more hot water volume than parallel. The outlet tank would be receiving hot on its inlet at the beginning, and always be getting warmed water near the end, whereas, if things were in perfect balance, the outlet would be constantly dropping as the things emptied when the draw is greater than the burner can replace.

 

[Fitter30]

T heir piped in parallel in the reverse return piping which is first in last out. This is the preferred method piping doesn't have to be the same length for even flow. Just wondered why a expansion wasn't installed on the cold line. Do you have a pressure reducing valve?