Two gas water heaters?

Why on earth would a builder install two 40 gallon water heaters side by side one plumbed to the other instead of just installing an 80 gallon? perhaps a faster recovery time?


Hot water heating?
Hot tub?

I dont know, but I have seen it often, just not on new construction.
Ask him and tell us what he says.

I have two at my house (50 gals). The reason: I didn’t have the space to go farther into my garage (diameter) with a larger heater, but I did have the space to put another of the same size next to it without coming out into the garage any more.

Secondly, if one goes out we can still function until replacement.


Never wonder why someone did something. It will only drive you crazy. Just report the facts. Was the installation properly done or not?


Was there a furnace in the house??? If there wasn’t than it’s probably to heat the house. I have seen this from time to time in this area.


I have two electric ones plumbed in series.
I have a switch on one and just turn it on when we have company.

When it is functioning as a storage tank, the cold well water in the tank gains some heat from the garage in the warmer months.

Dimensional restrictions makes the most sense to me and to answer the rest of you…
No hot tub
Yes they were installed properly
and yes to furnace

I will call the builder to get his take on it as well (if they will even talk to me) LOL

Thanks I will let you know what they say

Easier access when they need replacing, Usually much cheaper as the regular sized ones are much more popular and competitively priced.(supply and demand) And as others have mentioned, if one fails you still have one working…best of both worlds. Common practice in our neck of the woods, if you have a large family or fixtures that require a high volume of water to fill.

Commercial water heaters are very expensive and big and bulky.

Have you ever seen the price on an 80 gal Water Heater!!
Do you know how hard it is to find someone who has them in stock when you need one!!

It’s not likely that both will go bad at the same time!!!

I could never understand why anyone would install 1-80 gal water heater if they have room for 2-40gal water heaters!!!

Including installing bypass valves & the extra copper it is still cheaper to install 2-40 gal water heaters!

On top of that your recovery rate is far quicker.