I've never seen water heaters plumbed in series except for solar, where the first tank is hooked to the solar panels and preheats the water going into the second tank.
If somebody does plumb two regular heaters in series, is it best to have the first tank set at a lower temperature so it won't leak as much heat?
One will be more efficient if its Ng since the main heat loss is up the chimney, the uninsulated center. Research EF ratings, Energy Factor is the accepted rating for a water heaters efficency , Most ng WH are only 65% efficent. They range from 55- about 86 EF for tanks.
82-96 for tankless.
Wrong answer, it is not 1331 it is 1333. You forgot about you whining about it and me replying to you. ;oP
VD
One heater has less radiation loss than two. Volume goes up faster than surface area. If, by parallel, you mean split load, that's more about rationing hot water. Serial has more hot pipe to lose heat. If you tap off in the center, it gets more complicated. For long runs, you're still heating the water in the middle. Closer spigot means you get it faster, but for serial you're depleting both reservoirs. Typical electric water heater has two elements, but only one on at a time. No reason you couldn't run both elements if you had enough electricity available. BTUs are BTUs. The amount of water you can heat is independent of how many heating elements or tanks you have. It's all about the total electrical input. How much hot water you can have NOW is a function of total tank size.
I like mine at 145 minimum.
The most common application of series connected water heaters is a 5 gallon unit at point of use to provide hot water instantly, connected after the 40 gallon or whatever "main" heater which might be at the other end of the house. This saves water as you do not need to run the water through the pipes to get hot water, and you don't need a high powered heater at point of use, like the useless tankless systems.
Thanks. I'll try that too.
Old electric water heater had a hole in it to adjust the temp. New one has a solid metal plate and underneath that a biece of styrofoam filling the space. Have to remove both. A real pain, but I guess it saves heat.
I thought I posted alreay. I'll try 145 also. Thanks.
I should have mentioned both water heaters are gas fired and 50 gallons and they're both right next to each other (practically touching).
The hot output of one heater goes into the cold input of the other.
There is a hot-water recirculating pump on the output also that allows any of the five bathrooms in the house to have hot water within ten or fifteen seconds.
I will read all that is written here until I understand what the design goal was in the first place (and what then to set each temperature at).
They both are fired off the same propane tank (not natural gas).
This seems reasonable.
I have both set around 130 degrees at the moment.
I'm not sure which you mean by the 'first' and 'second'. I'll assume the first is the closest to the cold water supply and the second is next in line.
Are you suggesting something like 100 degrees for the first tank and 130 for the second tank?
Bear in mind there is a little black hot-water recirculating pump, which I don't quite understand but it runs a lot (I can hear the humming).
They are clearly set up in series.
I just want to know why anyone would do this and what I should set the heat at (both are currently set at 130 degrees) for each.
There is also a hot-water recirculating motor (which runs frequently).
I have it set to 130 degrees for both tanks.
When it comes out in the kitchen, it's a bit too hot to touch, but, the upstairs bedroom and jacuzzi are just right (which from experience means it's about 100 to 105 degrees if I remember rightly).
There is also a recirculating system which runs frequently (about once an hour or so) to allow the water to be hot quickly.
I had thoroughly searched and did not see the prior hot water heater in series question.
Did I miss it?
Interesting.
I might even turn OFF the first hot water heater (or set it to something really low, like 50 degrees or something).
The only one who uses a lot of hot water is the teenager (and that kid can freeze because there is no reason to take an hour-long shower anyway).
I wonder if this will affect the hot-water recirculating system adversely though?
My mistake for not being clear.
They are clearly in series.
The well pumps the cold water which goes to a four-foot high blue steel bladder tank which goes to the first 50 gallon hot water heater which goes to the second 50 gallon hot water heater in series which somehow goes to a hot-water recirculation motor about the size of a small bench grinder motor ... which goes to the bathrooms, laundry room, and kitchen.
My question is why (I'm slowly learning why) and what to set the temperature at (since it's currently set the same for both at about 130 degrees or so).
No reason for this setup except to heat 100 gallons of water in 2 50 gallon tanks. Maybe the expense of a 100 gallon tank makes it more economical to use
2 50's. If you don't need all this hot water you could turn off the gas on the one closest to the cold water supply and kill the electric to the recirc pump. If your water supply is cold the first tank would act as a tempering tank and would usually give you a longer duration of hot water from the active tank. Or completely disconnect the first tank and hold it as a spare. Sounds like your system is working as intended to heat 100 gallons. Up to you how economical you want to be. Heating and keeping hot 100 gallons of water has costs.--Vic
Well now I'm thoroughly confused.
It sure LOOKS like a serial connection.
The cold water from the well pressure system goes into the first hot water tank and out of the heat pipe of the first tank it goes into the cold inlet of the second tank and out of the heat pipe of the second tank it goes to the house with a recirculating motor somewhere on that final output (I can see the recirculating pump and I can hear it but I don't know exactly how it works.)
So, all that LOOKS serial. The house was built to code I would think, at least originally.
Plus there is that web site that explains serial hookups. So are you SURE that serial hookups would not be to code? Why?
Just for clarification, they're propane hot water heaters.
I see that I wrote this confusingly.
They appear to be in series (not in parallel).
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