Anyone use a tankless hotwater heater

1973911s · 01-30-2005, 03:50 PM

We moved the door to the house from the garage, and it is right next to the big 40 gallon hotwater heater, was thinking it would be nice to install one of those natural gas tankless hotwater units.

Anyone have any experiance with them?

Michael

red-beard · red-beard's Garage

My old house in western Mass used a combination oil furnace/tankless hot water heater.

Plus: It never ran out of hot water

Minus: It was a little undersized and you had to run the water slow or the water wasn't too warm.

Isabo · 01-30-2005, 10:09 PM

Constant hot water

As well as running the water slower, you can adjust the gas (not just the gas and water dials on the heater, there's a gas valve with the mechanical bits you can tinker with to increase the temperature. Especially important in the winter if your water is from an icy natural source in the mountains like mine

Rufblackbird · 01-31-2005, 12:32 AM

We've had a 220v one for years... First one lasted us a long time, and water was always hot. Second one is either way too hot, or kinda sorta hot.

Joeaksa · 01-31-2005, 05:02 AM

Used them in Europe for years, they work great. When my current water heater goes South its getting thrown out and replaced with one of the new ones!

JoeA

RickM · RickM's Garage

I recommended a pilotless/tankless unit to a friend and he had it installed about 5 years ago.

The most common brand/model in the U.S. is the Bosch Aquastar. Bosch purchased a French company a few years ago to acquire this technology. Which, as stated above, has been used for many (50+?) years.

Unlike a conventional water heater you simply replace the innard parts, typically coils, when they crap out. But that takes quite a while and is dependant on your hardness of your water.

Back to my bud, who installed the Aquastar....He loves it. However, when turning on a small faucet which is far from the unit expect to wait a bit. It'll take a little longer than a conventional tanker. To him not a big deal.

I'll be installing one when my unit looks to be on the way out.

BTW, when I mentioned the Aquastar to a few plumbers they looked at me croos-eyed. Apparently many don't even know they exist.

FastDave · 01-31-2005, 05:17 AM

2 out of 5 posts calling it a "hot water heater"....and I thought this was a regional problem, southern problem, hick problem or something like that....but I guess it's worse than I thought! ha

And for those of you who are as slow or backerds....It's a "water heater", not a "hot water heater"....why would you need to heat hot water????

Icemaster · Icemaster's Garage

Just installed an Aquastar two months ago. Fairly to easy to put in for someone whose savvy.

The only concern was sufficient makeup air. Bosch now has a model that's room sealed, pulling in combustion air from the outside.

I wouldn't go back.

RickM · RickM's Garage

Quote:

Originally posted by FastDave
2 out of 5 posts calling it a "hot water heater"....and I thought this was a regional problem, southern problem, hick problem or something like that....but I guess it's worse than I thought! ha

And for those of you who are as slow or backerds....It's a "water heater", not a "hot water heater"....why would you need to heat hot water????

Heh heh...good point. But technically the heater turns on to heat the water when it's still hot but fell to a particular temp. So the water in the tank never really gets cold.

gaijindabe · 01-31-2005, 06:03 AM

I think a lot of heat can be wasted keeping a whole tank of water hot. They are popular in country houses and small apartments for this reason.

In Japan they have a smal unit above the sink, and a hose that reaches into the shower room!

legion · 01-31-2005, 07:24 AM

I was looking into these. I opted for a larger tank unit because:

1) My wife wouldn't let me do the work myself, and I couldn't find a plumber willing to install them...

2) The store that was selling them wouldn't warrant them.

RallyJon · 01-31-2005, 07:55 AM

I've been looking into this, too. Here is the only unit I've seen that can actually substitute for a big tank heater in a decent sized house:

http://www.noritzamerica.com/n132.html

It's about twice as big as the biggest Bosch.

Leader · 01-31-2005, 10:04 AM

We renovated a smaller home last year and replaced two old-style water heaters with tankless units from Takagi. The main house unit will supply endless hot water to any two major sources (shower, washer, dish washer) simultaneously. Our gas bill has also been reduced (probably 30%).
The downside, as mentioned above, is that faucet outlets at a distance from the unit (like our kitchen sink) demand a smaller volume of water which means a delay in getting hot water. It's not a big problem, but worth knowing.

RallyJon · 01-31-2005, 01:22 PM

Then again, it takes 20-30 seconds of running the water to get hot water on the second floor from my big tank-style heater in the basement. How much longer delay is it with a tankless?

Seems to me that a tiny, say 2 gal. tank attached to it would solve that delay problem. Just enough to cover the lag.

Leader · 05:33 PM

The energy saving design of the tankless water heaters is that they don't produce hot water until it's asked for. In other words, when a hot water tap is opened anywhere in the system, the heater immediately turns on and begins super-heating water.
It's about 90-feet from my heater to my kitchen sink. It takes roughly 40-seconds before the water runs hot at that sink. What delays the hot water getting to most faucets is all the cold water in the supply pipe between the water hearter and the outlet. And since most newer fixtures are "low flow," it takes a while to evacuate that supply as the hot water moves toward the open faucet. In a larger-volume fixture, like a shower, the hot water arrives almost immediately.
What runs up your gas bill is the old-style water heaters keeping (40-60-80) gallons of water hot all the time. Putting a small holding tank on a tankless water heater kind of defeats the whole concept and wouldn't speed up hot water delivery.

RickM · RickM's Garage

Quote:

Originally posted by RallyJon
I've been looking into this, too. Here is the only unit I've seen that can actually substitute for a big tank heater in a decent sized house:

http://www.noritzamerica.com/n132.html

It's about twice as big as the biggest Bosch.

This is good to know. Thanks for the link.

With my needs may be overkill.

Something for all to consider when going to the larger units is that you need enough water/gas volume and pressure to drive these things. If you're going to use several water consuming appliances (Washer, shower, faucet etc) concurrently you need enough flow to handle. Tank or tankless makes no difference.

EDIT: Punctuation

mikester · 02-01-2005, 08:13 AM

What is the price point on one of these and the potential savings in energy costs?

RallyJon · 02-01-2005, 08:41 AM

They cost a lot. That link I posted lists for $3999. There are smaller ones that are around $1000-1500. Not sure what street price is, but plumbers around here make more than lawyers, so I'm not optimistic.

My main reasoning would be reclaiming a 4' x 4' x 8' section of prime basement real estate.

MotoSook · 09:13 AM

This is fun..

Back in college, my Engineering Design prof. had us design such a thing as a class excercise.

I designed an unit just like the instant hot water units we are talking about here, but with a small heated reservoir to make up for the ramp of the heater. The smaller reservoir requires less heat to maintain the set temperature than the larger tank WH we are use to, and it can be easily and effectively insulated. It was sized just large enough to displace the cold water in a run of pipe. It was a flow through reservoir that could be by-pass when the heating unit ramped up to so level. It's a little more complex that this explanation, but I think y'all get the idea.

Most homes in the midwest have the hot water heat fairly close to the kitchen, but as we all know, it takes a bit of time before the flow is hot in our showers and bath tubs. A small "make-up" unit could be place in the master bedrooms of America to provide warm water to the shower until hot water was detected from the normal flow path. Imagine the savings in time (no more waiting for the shower to heat up) and water.

Thank you! Thank you very much..my resume and salary history is available to the right employer

RickM · RickM's Garage

Keep in mind there are small electric units that go into those remote bathrooms for quick hot water. Takes up the slack so to speak.

The Aquastar fo rthe average home can be had for around $1200 if ytou look around. It gets more expensive if you need to plumb in the optional flue attachement.