Hot water

[TimWhalen]

Currently I have a 30 gallon electric hot water heater providing hot water to a 3/4 bath (shower and sink) used by two people.

I am trying to convince myself that I can pull from this same hot water heater to another new bathroom (shower, tub, dual sinks). When all is done three people will utilize these two bathrooms.

Is this feasible or shall I look for another alternantive?

[Tom Raymond]

As long as the teenager showers last you will have plenty of hot water.

[kurt]

Yeah. Any teenagers in the house pretty much cans a 30 gallon heater.

You want to ramp up capacity a bit. If you're into water saver showerheads and being meticulous about water consumption, you could make it work, but you probably won't like it.

[David Meiland]

How old is the 30?

[TimWhalen]

9 years old...it was not used a whole lot until two years ago when we moved in.

[mjr6550]

A 30 gallon electric water heater is 20 gallons less than typical. I also wonder whether it has 4500 watt elements. If everybody takes short showers and can wait between showers for it to heat the water you may be able to live with it. I suppose there is no harm in trying, but I would be thinking about a new water heater.

[John Kogel]

Tim, you like to play around with parts and tools. Install a second tank and plumb it series/parallel with hookup valves.

Then you can pre-wram your water, or run one tank to each bathroom. Then you can report back here which is best. [:-graduat

[Erby]

If you're doing two tanks, do them in parallel not series.

[Tom Raymond]

Series only works in solar thermal installations.

Go big or go parallel.

[rjmiller]

Series is useful to avoid flushing previously hot water down the drain. Typically a small tank is used with a 70% usable capacity equivalent to the volume of the pipe between the primary tank and the tank at the fixture.

[David Meiland]

At 9 years, it's probably reasonable to just replace the 30 with a 50. You might also be able to add a circuit and wire it so that both elements fire at once. If you have the installation manual, take a look and see if there's a diagram showing the wiring for that. If it only has one element, forget it.

[Les]

Series only works in solar thermal installations.

Go big or go parallel.

Tom, why? I have series with no issue.

[Marc]

Series connected heaters seems to have Rheem's support.

Download Attachment: Heaters on series_parallel.pdf

87.34 KB

Marc

[John Kogel]

See what I mean? Parallel is better for what reason?

We need more data.

Re: size of the second tank. You will see that the standard size tanks are cheaper than the odd sizes, bigger or smaller. I had to fit a smaller tank into a closet and ended up paying almost $200 more for it.

I would go series because I don't think you will always need 2 tanks. If you put the new tank downstream from the old one, you can shut power off to the old one and it will temper the well water, bringing it up to room temp. That alone will save you energy. When your teen is around, turn it on at a lower temp setting to preheat the water to the new tank.

If you find you run out of hot water, slap kid up the head turn up the temp on the first tank and have about 60 gals of stored hot water.

If you can figure out a timer arrangement, one tank could shut itself off for half of the day.

For parallel, you need to equalize the pipe lengths and restrictions so that both tanks supply equally. Advantage is one tank can be shut completely off, like when it springs a leak.

[John Kogel]

You might also be able to add a circuit and wire it so that both elements fire at once.

That's a resourceful solution, but I think you should emphasis that a new circuit needs to be added all the way from the breaker panel. Wiring the two elements to the one supply circuit would be a serious fire hazard if it doesn't trip the breaker.

Also assuming it is an electric water heater. Most of the mainlanders burn gas, eh? []

[TimWhalen]

Thx to all. I will digest everything and report back.

The other wrinkle to all this....

The house was carved into three apartments 40 years ago. Each of the 30 gallon tanks serviced one apartment each on the second floor. Both of these are electric.

The 'main' apartement is on the first floor and has a 50 gallon gas fired unit. I'd like to leave this one alone.

Before we renovated, each apartement on the second level had a full kitchen and bath. I did away with the kitchens and updated both bathrooms. All is well with three teenage boys in one and one teenage girl in the other. As I move forward I am speculating that kids will leave for college, etc as well.

My head hurts.

[David Meiland]

He said electric, and I said add a circuit... which I suppose could be made more clear by inserting the word "new" in there too.

[Tom Raymond]

I recall another article advising against series installations because the second tank always ran more than the first and wore out sooner.

[Marc]

I recall another article advising against series installations because the second tank always ran more than the first and wore out sooner.

What was said to be the problem with one wearing out before the other?

Marc

[John Kogel]

I recall another article advising against series installations because the second tank always ran more than the first and wore out sooner.

What was said to be the problem with one wearing out before the other?

Marc

The problem was plumbing leaks from rotating them twice a year. []

David, my apologies. I read it too fast, I guess.

[Les]

I suppose that would be common sense that one dormant would not wear as much as the active. However, my recommendation, for our areas, is the lead tank is set to just above 60degrees which is 5degrees above supply and the second tank finishes the work at 120+-. That seems to be right for us here in Michigan where our water is really not problematic in most areas. I suspect this arrangement saves me a few dollars on my natural gas bill and I know we are never out of hot water with four bathrooms and two kitchens. With me, the wife and a couple cats, it gets close at times!

[tim5055]

I suppose that would be common sense that one dormant would not wear as much as the active. However, my recommendation, for our areas, is the lead tank is set to just above 60degrees which is 5degrees above supply and the second tank finishes the work at 120+-. That seems to be right for us here in Michigan where our water is really not problematic in most areas. I suspect this arrangement saves me a few dollars on my natural gas bill and I know we are never out of hot water with four bathrooms and two kitchens. With me, the wife and a couple cats, it gets close at times!

This is what I did a year ago. The house we bought already had two 50's in series. As it is the two of us with 4 cats and a German Shepherd Dog 100 gallons at 120 was more than we would ever use. I turned the lead tank down to pre heat the water going to the finish tank. So far so good.

[Tom Raymond]

An uninsulated tank would reach 60 most of the time just sitting at n my basement. No fuel needed.

Marc, the second tank experiences greater temp swings. It runs more frequently and for longer periods than the preheated. As a result it also sees more condensation. I've been in my house less than 15 years and have installed 3 water heaters there. The last thing I need to do is hasten the detritus.

[rjbrown2]

My small sample experience with electric water heaters is that 9 years is just a fraction of their useful life. Depending on water chemistry, the biggest problem I have found with electrics is the cal-rod burnout due to 'mineral' deposits. I had one unit where I had to replace the lower rod on an 18 month cycle. I wedged a stainless steel 'fin' against the base between the rod loop and extended the life to over three years.

[plummen]

I suppose that would be common sense that one dormant would not wear as much as the active. However, my recommendation, for our areas, is the lead tank is set to just above 60degrees which is 5degrees above supply and the second tank finishes the work at 120+-. That seems to be right for us here in Michigan where our water is really not problematic in most areas. I suspect this arrangement saves me a few dollars on my natural gas bill and I know we are never out of hot water with four bathrooms and two kitchens. With me, the wife and a couple cats, it gets close at times!

This is what I did a year ago. The house we bought already had two 50's in series. As it is the two of us with 4 cats and a German Shepherd Dog 100 gallons at 120 was more than we would ever use. I turned the lead tank down to pre heat the water going to the finish tank. So far so good.

That's how I would plumb them normally,gives you more reserve/faster recover without having to keep 100 gals of water constantly heated.[:-thumbu]