Beepster, we'll look into that. Thanks. I can't remember how all the pipes run, but surely somebody knows.

Thanks Craig...that's what I was looking for...Energy Star symbol. Thanks.  But be careful of the crazy ideas...my son is reading this thread (and appreciates the great ideas!), and, well, the neighbors may not appreciate him shooting a water tank. :) 

Beepster...same goes to you.  lol

Julien...thanks. I didn't know that.  I'm glad I didn't call it a hot water heater either.  I'm sorta surprised I didn't.  :) 

Thanks Bub.  That's all very helpful!!

Beepster


If your plumbing is installed in a semi vertical line (like your laundry room, kitchen and bathrooms are all in the same general area of the house but on different floors which is how many homes are built) then one large unit in the basement will suffice provided you aren't feeding hot water to more that two or three floors. However if you have sinks elsewhere in the house you can get small units to provide hot water to those taps. The idea is you don't want to have to drain all the water that is already in the pipes to get to the hot stuff. This is also a good idea for saving energy even with a tank system but the water in the tank is already heated so the cost difference is minimal to feed taps in more remote locations of the home. Whereas with an instant heater you are paying to heat water that won't be used. I hope that made sense... I'm a little scattered at the moment. :-)

Regardless of the source, the water in the lines will loose heat. Even in an extremely large home, at worst, you will waste a quart of unheated water.
Tankless(instant) water heaters are significantly more efficient than storage tanks. They only heat the water on demand. BUT, they are initially expensive. If you own the home and plan on staying there, they are viable. You can expect a return on your investment in about five years. After that, it pays for itself. I believe in gas tankless systems, but am not entirely sold on electric.
In your situation, Janet, it appears that electric is your only option.
I would get a 40 gallon storage tank. Dual elements should be pretty standard.
Set the temperature to 140. Less than that breeds bacteria. A timer is a good idea, but set it to at least an hour before you expect to need hot water. Heating capacity should meet or exceed your anticipated demand.
Very hot water can be diluted, and is ultimately more efficient, and safe. Warm standing water is dangerous. Period.
You know my background.

Yes, I do, Bob, and I highly respect your opinion. Thanks so much!  (my son just told me his wife won't tolerate anything less than 140 for her showers anyway). :)  

Thanks again...I appreciate you chiming in here! 

@Bub... Yeah, man. Good info. I will point out that 8 years ago the tankless phenomena/tech was still in it's infancy here in the west (they've been used extensively in UK/Europe for a long time) so the newer tankless units are probably far better built these days. In fact during the time period you got yours I was looking at them and even the building codes hadn't been sorted out for them in my area yet so I ended up buying and installing a tank. But to elaborate on the pipe run issue (which is what I was kerfuddling about earlier and not explaining properly) is that you have to look at it in two ways. With a tank the elements will constantly be turning on and off to maintain the temp of the water in the tank so that hydro/gas is already spent. Sure they'll work harder heating up a fresh tank of cold water but it won't be a constant "ON" scenario like a tankless. Also a tankless will draw WAY more power because they need to heat the water instantly. With the tankless you do not have the constant "ON/OFF" of the elements though even when hot water is not being used. So really it comes down to an equation of how much hot water is being used regularly and how far does it have to travel. If you have a large home that requires the hot water to travel great distances to get to it's destination and/or use a LOT of hot where a tankless element will be constantly "ON" then a tank may be the better option. However if you can afford to have true point of use heaters installed under all or most of your fixtures you will end up saving money on hydro/gas and likely significantly increase the value of your home. Again I will point out that in light of current environmental incentives you can get tax breaks or rebates by going the tankless route as well so definitely look into that. Cheers!

@Robert... I completely agree but the elements do run hotter so (and I may be wrong because I'm no mathematician) having the tankless elements running the whole time while waiting for it to come out of the fixture would likely use more energy than a tank... but obviously the tank will use far more energy maintaining it's own temp in the long run. So in low usage homes that long run wouldn't be such a big deal but in a home with a large family in it it might make a difference. So yeah... use a big tankless for the main plumbing stack and the smaller point of use unit for fixtures further away. At least that's how I was taught to do it.

I talked with a plumber last year about installing a hot water recycle unit. It is just a pump on a timer that cycles the hot water through the pipes every 30 minutes. Insulate the pipes and you have instant hot water all through the house. I had forgotten about it, I need to get it done.

@jbow... ??? How does that work? Sounds like it would just make the tank work harder.

If you have a long run of hot water pipe it can take too much time for the hot water to get to where you want it. A cycler and insulated pipes sort of uses the pipes as more tank. Insulated copper pipe isn't going to lose much heat in 30 minutes, so it is just putting hot water back into the water heater. It is a matter of convenience mostly. I am going to add an extra water heater too. I have a 40 gallon short tank. It is in the crawl under the master bath but filling a bath in the garden tub deletes the supply of hot water. The guest bath is upstairs on the other end of the house and it takes a couple of minutes for hot water to get there, give or take... it seems like a long time. I would just cycle the pipes in the crawl. I need to get it done. I had the breaker installed and the wiring for the extra water heater put in.. then it slipped to the back burner.

You may be right. I will check it out more and maybe just add the extra tank. Thanks for the thoughts.

J

Beepster


@Robert... I completely agree but the elements do run hotter so (and I may be wrong because I'm no mathematician) having the tankless elements running the whole time while waiting for it to come out of the fixture would likely use more energy than a tank... but obviously the tank will use far more energy maintaining it's own temp in the long run. So in low usage homes that long run wouldn't be such a big deal but in a home with a large family in it it might make a difference. So yeah... use a big tankless for the main plumbing stack and the smaller point of use unit for fixtures further away. At least that's how I was taught to do it.

The tankless elements(or burner) use zero power if water is not flowing through the unit. That's the whole idea, really.
It only fires up when hot water is needed. A normal gas water heater is rated at 40,000 BTU's. this is a fairly constant usage.
A gas tankless water heater needs 200,000BTU's when it is running. While this may seem high, realize that this sort of demand is limited to maybe 20 minutes out of an average day. The temperature of the water is increased 90 degrees while passing through about 15" of pipe in the unit in a matter of seconds.
For a large family, a properly installed tankless unit is sweet. You can take five showers back to back, and the last person has hot water. Not so with a storage tank.
fwiw I am a 15 year plumber, trained in tankless installations. They are not right for every situation, but can be gold when they are.

Jbow, a recirc system may be just what you need.
It will maintain hot water to the most remote bathroom if properly installed.
It is most suitable with a storage tank,but it can be done.