While a I have a system with a DSH I know it is inefficient, however the setup is how I purchased the house. Currently the DSH is supplied and plumbed back into a 50 gallon AO Smith electric hot water heater in a conditioned space. I do not have a storage tank, which is where I believe I loose efficiency. The current water heater was installed in ~2009; I've done the basic PM of replacing the annode rod to prolong the life. Given that I have a 50 gallon tank already do I just add a second 50 gallon heater and use two equal size tanks? One as a holding tank and one as a heater? Should I scrap currnet 50 gallon heater and but two new heaters of equal or different sizes (doesn't make economic sense)? There are four of us in the house now; generally we do not run out of hot water with the current setup. Practically speaking, what is the most efficient balanced by economic combination of tanks. Thanks Mark
I chose just a 40 gal holding tank, figuring that it will get warmer quicker then a large tank. I picked up a discounted scratch & Dent at the big box. I use a heat pump water heater for my finish tank and leave it on heat pump only.
I 2nd Chris J's advice...inexpensive 40 or 50 gallon water heaters serve nicely as "holding" (actually, preheat) tanks. If it is easier, simply buy another 40 or 50 gallon storage tank water heater, install it down stream of the existing tank heater and move the electric circuit from existing to new...that way no need to move the desuper plumbing (assuming it was done right in the first place)
Thanks for the validation and not making my think this is more complex than it needs to be. As Chris J suspected it should be as easy as setting the new tank next to the existing one, moving the electric service and a little basic plumbing to add it in. For a DIY'er it will be a half day project --including going to the store to get the tank and rearranging things in the utility room.
