On Demand Water Heaters

[Flybye]

We are home from Kauai. Just got in yesterday afternoon. We are exhausted, to say the least from the red-eye flight home. We have been greeted by a leaky water heater. We have know that it was on its last leg for at least a year but have been helping it limp along. It is an electric heater that we purchased with the home. Now we have to get back to reality and get busy drying out carpet and fixing the heater.

Do any of you have an on demand water heater? This is one option that we are seriously considering. It is pretty pricey, as we will have to vent it to the outside, get it hooked up to natural gas, and have a new water softener put in.

The other option for us is to piggy back two gas water heaters which would still involve venting and purchasing a new water softener and getting the heater connected to gas.

We need enough hot water for a family of five. I understand that there is a two appliance max at a time that can run on the heater.

Any advice or opinions?

Thanks...


I'll post pictures later....we took a bunch!

[maillotpois]

From what I have heard, talking to people in the business, this is the way to go. Environmentally better, saves money in the long run because you're not holding a big pot of hot water staying heated all the time - just when you need it. I would absolutely go this route if we could.

However, the other thing you need to check out is to make sure that your plumbing is adequate to support this type of water heater. One of the guys I talked to, a client who specializes in radiant and on demand, said that in a lot of older houses not only do you have to deal with the venting issue (he recommends just mounting them on the outside to deal with that), but the plumbing may need to be upgraded as well. (Has to do with the BTUs and all, but I don't recall the specifics.) So check on that with your house.

You might see if there's some sort of energy saving rebate program available in your state for upgrading to this system.

[LBTC]

Fly, I asked DH about this as he spent some months as an apprentice plumber recently, and learned a bit about it. A direct quote of his reply:

Ok....going to an on demand heater is an expensive proposition. The pay back is a long time, and the initial cost to install is probably 4-5 times the cost of a gas hot water tank. The venting is the same as a high efficiency furnace, so it would be best if she can install it on or near an exterior wall. Electric tanks are more efficient when idling, versus a gas tank, but the recovery is slower. The on demand systems take awhile to provide heat if you want a quick blast of hot water, say to wash your hands. The bonus to the on demand is that they use no energy when not in use, and they never run out of hot water. They just have an initial huge cost to install and long payback. Remember that she will be looking at gas lines, venting and plumbing. If she's good with that.....go for it.

The cheapest way to do this is to twin 2 electric tanks. I've done it, and it's fine.

That said, I do seem to recall that he said that in an older house there may be water line upgrades necessary, also, so it may depend on the age of your plumbing, too.

Best of luck with this. Sending fast flying butterflies so their wings will help to dry out the carpet!

Hugs,
~T~

[sundial]

We are home from Kauai. I'll post pictures later....we took a bunch!

Welcome back! Where's the pics?? Oh, and take a pic of your new water heater(s) too.

[IFjane]

flybye - we are also considering this. We purchased a home in 2001 that was built in 1981, along with the electric water heater (we have no idea if it is original or not). Last year we replaced the heating system with a high-efficiency gas furnace with a heat pump backup - love it! Big investment but much lower monthly energy bills. I expect the same thing from the hot water heater.

Please keep everyone posted if you decide to go ahead with this. We are waiting until the hot water heater dies as well....

[tulip]

The condo I reserved has a regular hot water heater (but a half-sized one since it's a half-sized condo!) The developer said that the electric on-demand water heaters have some reliability problems, and there's no gas in the building (unfortunately for me, as I like to cook, preferably on a gas stove).

[tc1]

And is a lot less aggravation. You might be surprised at the amount of cost and bother required to retrofit an on-demand system.

The thing about electric heaters is, you should replace them every ten years. What happens is they develop rust and pinhole leaks at the top. By the time this is discovered, the heater has been leaking small a small amount for weeks, if not months.

For fast drying of the mess, go to a rental store and get a commercial blower/fan, and a dehumidifier. I also rented a commercial carpet cleaner when this happened to us, and was able to get the carpet better than it looked when we moved in, with no mildew.

O'course putting all the stuff back into the storage room is another topic altogether.

[divingbiker]

I attempted to get an on-demand gas water heater when mine died last year, but it was going to cost so much and take so long to get it done (and I'd be without hot water in the meantime) that I ended up getting another gas heater. My only experience with on-demand heaters is at my office, where each kitchen has a small heater under the sink. Those are unreliable and annoying.

[Pax]

My dad (who was a retired contractor) decided the on-demand stuff was too expensive when they bought their place in FL, since it was an electric hot water heater, he just installed a switch (like a light switch). They would flip it on before bed and have hot sowers in the morning and then flip it off on their way out the door to work. It was a $2 solution, don't know if it would work with gas though?

[Flybye]

Well, after much decision and debate, here's what we have decided...........

As much as we would like to be responsible and save the planet, we still have to feed our children!

We just can't talk ourselves into putting in the on demand water heater when it will cost roughly $1,500 more than if we go with either electric or gas. Not only is the cost a huge deterrent, but the power venting system is troublesome, our home was built in 1970 and the pipes may not be up to snuff, and we have heard that since our ground water is so cold in the winter, we may only get our temperature up to 105 at best in the winter.

We have decided that it just isn't worth it at this point.

All of your opinions and knowledge helped a great deal, as we really didn't know too much about these heaters. You all brought up things that we hadn't considered.

The carpet is pulled up and we have a fan on it.

We are waiting for the plumber.

Thanks again! Mahalo!

[Flybye]

My dad (who was a retired contractor) decided the on-demand stuff was too expensive when they bought their place in FL, since it was an electric hot water heater, he just installed a switch (like a light switch). They would flip it on before bed and have hot sowers in the morning and then flip it off on their way out the door to work. It was a $2 solution, don't know if it would work with gas though?

I like this idea and we will be sure to ask about it!

[7rider]

I like this idea and we will be sure to ask about it!

My in-laws did something like this...had a timer attached to the w.h. somehow....so it fired up the water up b/f evening showers (they showered at night) and dish-washing.

[mimitabby]

I'm getting a tankless gas water heater TOMORROW!!!

[IFjane]

ooooh ooooh ooooh Mimi!!! I wanna know how you like it - that's exactly what I want to do...

[mimitabby]

i'll let you all know. one of the wonderful parts of this is I get a new room because the old waterheater blocks it from being usable. the new one is much smaller and mounted on the outside of the house!