I am trying to hook up 2 hot water heaters in one house, (natural gas). I know how to hook up one tank, but not 2. please help.:confused:

I am trying to hook up 2 hot water heaters in one house, (natural gas). I know how to hook up one tank, but not 2. please help.:confused:
There are two types of hookups. Series and parallel. Before I can answer I need to know the reason you're doing this. Separate zones for hot water distribution?
Increased storage capacity? Using one for a "kicker heater"? The hookups are different for different applications.
Regards, Tom

There are two types of hookups. Series and parallel. Before I can answer I need to know the reason you're doing this. Separate zones for hot water distribution?
Increased storage capacity? Using one for a "kicker heater"? The hookups are different for different applications.
Regards, Tom
I am try to increase the capacity. Thank you Tom.

Do you have the ducting capacity to vent an additional gas fired hot water tank?

Improperly installed or undersized exhaust ducting can lead to carbon monoxide poisoning.

Good point Growler,
Do you have the ducting capacity to vent an additional gas fired hot water
Tank?

I think if I wanted to increase my hot water capacity I would opt foir a larger single hot water heater, the reason being it's cheaper to operate one burner then two plus you have half the maintenance.
But to answer your question you would hook them up in parallel. One cold water feed for both cold water inlets and both hot water outlets tied together and connecting into the hot water main. Good luck, Tom

The way that I will hook it up in my house :

There will be 2-40 gal gas water heaters that are side by side. You want to make sure that you have not only the exhaust capacity, but also the fresh air capacity. For exhaust I am going to use a 3x3 to 5 inch collector. I will have to enlarge the current chimney opening to accommodate the 5 inch. I am also going to install a fresh air combustion kit. This will bring in air from the outside, so I do not use too much oxygen from inside the house. It is code for houses that are built before '74, check your codes.

I am going to give each heater a cold water feed. I will designate one primary and one secondary. The primary hot outlet will feed the house supply. The hot from the secondary will go into the drain for the primary.

I am told that this works very well.

Check the codes in your area.





Good point Growler,
Do you have the ducting capacity to vent an additional gas fired hot water
tank?

I think if I wanted to increase my hot water capacity I would opt foir a larger single hot water heater, the reason being it's cheaper to operate one burner then two plus you have half the maintenance.
But to answer your question you would hook them up in parallel. One cold water feed for both cold water inlets and both hot water outlets tied together and connecting into the hot water main. good luck, Tom

Hi,

Come out of the wall with cold supply and tee off to each cold inlet of both water heaters and make sure it is equal length to each inlet. Have the same with the hot side of the heater outlet and into 1 hot supply to fixtures. This is if u are planning to set up to have the extra hot water and better recovery rate.

Hey Argalu
Thanks for the imput but You're responding to a 4 year old dead thread. Look in the upper left hand corner for the date of post.
Regards, Tom