On Demand Water Heaters

[smilingcat]

When I visited my cousin, my uncle and his family and my aunt in Japan, they all had those tankless water heater. I didn't notice any difference between the tanked system here in US and the tankless system used by my relatives.

I've been trying to get my plumber neighbor to install one. He is driving me bananas!!

My plan is to use solar water heater system using the evacuated glass heat pipes and use a 40 gallon? storage tank. Then use the tankless system as a back up. The idea is to use much of the solar as possible so that the tankless will remain off for the most part or only have to heat the water by additional 10-20 degrees instead of 60-80 degrees. This way I don't have to worry about running out of hot water in the evening.

So my patience is being tried...

Smilingcat

[derailed]

A comment, if I may.

On top of every tank-style water heater is a large heavy nut.
This nut is connected to a long, zinc rod.

It's not easy, as the tank must be off and completely drained, but replace this rod every 3 or 4 years, more often if your water is troublesome.

This will drastically mitigate tank-rot.

There are how-to guides all over the web explaining in detail.

[tulip]

When I first posted in this thread, I was looking at a condo. But I ended up buying a little house instead. The old hot water heater was toast, so I replaced it. The cost difference between a tankless and tank heater was so great, that in my case it just did not make sense to go with the tankless ($4,000 vs. $800).

The new electric tank hot water heaters are very efficient--more efficient than the gas tank heaters because gas heaters need to be vented, and that allows some of the heat to escape. The plumber said the electric tank heaters lose 6% and the gas ones 30%. The new electric tank heaters are like a giant thermos--very well insulated and once the water gets heated, it takes very little energy (about 1.5 hours per day) to keep it at the proper temperature.

A tankless water heater was not appropriate for my situation. My plumber said that Rinnai tankless heaters are the best of the tankless, FWIW.

[Biciclista]

Tulip, the price differential is scary, yes. But modern water heaters even though they are more efficient, they do not last as long as the older ones could.
Ours was 27 years old when we replaced it, and although it was an energy hog, it never leaked. I was assured by everyone that came to give a price quote that new ones didn't last more than 12 years.

[Norse]

Our 8 year old gas water heater has been a problem every winter from day 1. When the gas furnace is kicking in, the water heater pilot light frequently goes out - not enough oxygen in the basement apparently. Many "experts" have looked and scratched their heads, adding bigger holes and venting to the outside, drilling holes to the garage... but nothing has seemed to work. Every winter, we need to relight the heater about every other day. So, we want to replace the darned thing.

I really like the idea of the tankless heaters but based on our existing venting problem, it sounds like that will not work well. We also have an older house (1955) with older plumbing. Our idea is to replace the heater with a gas heater with electronic ignition. I have always preferred gas to electric because of the perceived efficiency and better for the environment issue but Tulip's comments have me thinking maybe we should go electric? Thoughts?

[Biciclista]

The tankless heater is on an outside wall fyi.

[Norse]

The tankless heater is on an outside wall fyi.

I don't think that would work well in Minnesota. Right now, it is a balmy -6 outside.

[ny biker]

When I first posted in this thread, I was looking at a condo. But I ended up buying a little house instead. The old hot water heater was toast, so I replaced it. The cost difference between a tankless and tank heater was so great, that in my case it just did not make sense to go with the tankless ($4,000 vs. $800).

The new electric tank hot water heaters are very efficient--more efficient than the gas tank heaters because gas heaters need to be vented, and that allows some of the heat to escape. The plumber said the electric tank heaters lose 6% and the gas ones 30%. The new electric tank heaters are like a giant thermos--very well insulated and once the water gets heated, it takes very little energy (about 1.5 hours per day) to keep it at the proper temperature.

A tankless water heater was not appropriate for my situation. My plumber said that Rinnai tankless heaters are the best of the tankless, FWIW.

Tulip, this is good to know.

I think I might need a new water heater for my condo, and everything is electric here. I don't know for sure how old my current water heater is but I think it might be approaching 15 years old. (Former owner told me it was "about 10 years old" when I bought the place, which was almost 5 years ago.)

I live on the 2nd floor of a 3-story garden style condo building, and the water heater is in an attic space on the 3rd floor which is not easy to get to. I'm trying to get my hands on a ladder tall enough to get me into the space so I can check it out. Originally I was going to put an insulating blanket around the heater, but now I'm figuring that I will probably just replace it, rather than keep it and wait for it to cause a big mess when it starts to leak. And a newer one should cost less to run since the insulation will be better.

Thanks to everyone for your input on this subject. It's so great having all this information available.