That's the first time I've seen a heater plumbed that way.
Mostly you will find that the connections for the water heater are above, not below.
We're getting ready to install a Rheem Fury Electric Water Heater. We are using 18" copper flex water supply lines and then Pex. The instruction manual shows installing the supply lines in either a vertical or horizontal fashion. The problem is that the horizontal version shows three 90 degree bends in it - something we'd rather not have to do with the flex lines.
Here is a picture from the manual:
According to the manual the thermal expansion tank is not required for an "open system" as our system is but I was curious about the "heat trap - 6" minimum" that is shown on the diagram.
Our plan is to attach the water supply lines and bend them in a gentle curve to make a single 90 degree turn, then attach a shut off valve that would connect to Pex on the other end. All of this would be above the tank. Does anyone see any problems with this? Incidentally, in another section of the manual, it shows the water supply lines mounted vertically, going straight up from the top of the tank.
Thank you for your help.
Last edited by Terry; 03-22-2011 at 10:14 PM.
A heat trap is there to help minimize standby losses. It does this by minimizing convection loops in the water. There are other ways to perform that verses what is shown. How well any of them work is somewhat in question. There are engineered heat traps that can be installed in the top of the WH that have either plastic balls or flaps that only open when you open a valve to enable flow. When there's no flow, they close, and limit the convection. If I was going to add one, I'd probably do that verses the way it is shown. Just make sure you get the pair installed on the proper sides, or you'll block flow when you want it.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013
I just replaced my 24 year old 66 gallon Sears WH with an 80 gallon Sears. It came with heat trap nipples. I used two 24 inch flexible connectors to make a heat trap loop that extends up about 10 inches or so. You can feel a BIG difference in temperature on the "downhill" side of the loop during periods of no water flow. It works so well I wish I had removed the heat trap nipples to get more water flow. I am sure that the little added cost will pay for itself many times over during the life of the WH.
ANY downward bend creates a heat trap, but most modern heaters come with "heat trap" devices already installed.