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I've been hearing about these for years, they eliminate the need for a 60 gallon (or whatever size) water heating monstrosity sitting in your garage by heating water on demand. In theory it sounds great, a little box on the wall taking little room and saving electricity or gas by not constantly heating water all day long that you're not using. Anyone have one of these, and how do you like it?

I don't have one; however, I've been told that they are best for new construction. Too much has to be done to replace a conventional hot water heater with the tankless system.

Hopefully someone who knows more can give you more information.

My DH was in the HVAC business (also water heaters) for more than 40 years. He's definitely not a fan. Here are some reasons why not:
http://www.consumerreports.org...water-heaters-ov.htm

Take special note of the sentence in the second paragraph that explains how the payback period of these high-priced units often exceeds the life of the appliance.

We installed one, removing a monstrosity, and love it!

Well, have to admit that I don't know much about tankless water heaters BUT, if it is the same as the "instant" hot water delivery via copper coils guaranteeing instant hot water delivery throughout a two story house being promoted a few years ago? Well, don't hold your breath.

It takes just as long for the water to heat up as it would if we didn't have this so-called advanced system which cost quite a bit, btw. Jury is out on this one; meanwhile, I wouldn't spend one penny on this "new" idea until I see facts and figures to back up the claims...

Not exactly sure which "new" system you're referring to, Idaho.

Tankless systems have been used for many years in Europe. I first used them over there. Incidentally, our system's much more efficient than their units.

We have a large rancher. Even with multiple, large water heaters, we had difficulty obtaining hot water in the farthest reaches of our home unless it was already available, i.e. in use within that zone.

We've had only 1 tankless unit in place for more than a year and do receive instant hot water, as promised. Needless to say, we're very happy with it.

Bearcat, did you see a change in your electric bill because of it? I've heard it can increase.

Considered one a few years ago but the price was very high. I don't know if the prices have come down but it was simply too much. If I remember the Rinnai was about $2000 or so and we had already spent a small fortune on the bathroom remodel so we passed on it.

We had a tankless hot water heater in a two story house and it was gas....didn't use all that much gas.

Haven't noticed any change in the electric bill, Elsie.

Both the previous water heaters and the tankless unit operate on gas. The gas usage's definitely gone down.

I don't have a tankless unit, but did work as a volunteer at a county park where they were installed in the shower houses. They worked wonderfully there. No shortage of hot water for hundreds of users. The head ranger said the propane consumption dropped dramatically when they were installed.

If your house has water usage points on opposite sides of the house you'll want a special re-circulation pump or you'll have a long wait for hot water. You don't want one that re-circulates the water all the time, that will defeat the purpose of the on-demand water heater. They make pumps that you turn on for 15-30 seconds before you turn on the tap to get the unit running and hot water to the tap without running the water down the drain.

The units also need professional descaling on an annual basis, maybe less often if you have soft water. If your water is hard they will clog up with lime scale.

If your house has all the water use points close together they can be quite efficient.

Before replacing an aging water heater, I seriously considered a "tankless" on demand hot water. Because water isn't metered (yet), utilities (relatively inexpensive natural gas), and homes plumbing configuration, cost effectiveness was iffy.
Next year, I may be sorry I didn't rethink long term benefit

This message has been edited. Last edited by: tessa89,

I've seen something similar to this overseas, in spoor Asian countries. I've seen a unit similar to this, but smaller, connected directly to the shower unit.

This might work for a poor small village in Asia where it's cheaper to have this than an entire heating system. It's probably more practical for them in a tropical climate.

It might be different in the western countries where our HVAC systems are more complex and our climates are much different. Sounds like a neat idea, but is it necessarily compatible and effective with our systems in our towns? heat and air tulsa

We had one on our shower when we lived in Central America. It worked to an extent but if you turned the shower on full, it was colder. If you turned the shower on slower, it was hotter. Was good "in a pinch" but really wouldn't recommend it unless that is all you could do.

quote:

Originally posted by Sparky:
If your house has water usage points on opposite sides of the house you'll want a special re-circulation pump or you'll have a long wait for hot water.

Thanks, Sparky! That is exactly what I referring to in my earlier post ~ the hot water heater is located in the garage at the west end of the house and the master bathroom is located on the second level on the east end. Maybe I spoke too soon about its limitations ~ might be that it would take even longer to get the hot water there without this system....

The systems mentioned above for Central America and Asia are at least a couple of generations old and not comparable to the systems currently available and typically installed in the U.S. Appears the purpose of the Asia post was an embedded advertisement -

BTW, we had a recirculation system with our previous water heaters and have no need to manually turn a pump on with the tankless system.

They need high-power electricity, 440 I think, the same you need for an electric oven or electric dryer. The 110 or 220 available in most bathrooms isn't enough.

There's one in the bathroom nearest my office at work, but they didn't get the power right so that bathroom has never had hot water.

quote:

Originally posted by JoW:
They need high-power electricity, 440 I think, the same you need for an electric oven or electric dryer. The 110 or 220 available in most bathrooms isn't enough.

There's one in the bathroom nearest my office at work, but they didn't get the power right so that bathroom has never had hot water.

Most homes do not have anything higher than 220/240. Residential tankless water heaters work on 220.

I know next to nothing about electricity.

Apparently all you need to run lights, computers, and copier/printers is 110. All whe have in the office space is the same low-power I have all over my house. And the tankless water heater in the restroom needs 220.

Thats something anyone installing a tankless system needs to consider. The bathroom in my house does not have the higher voltage, either.

In general, newer, current generation systems are installed in utility rooms - not bathrooms.

quote:

Originally posted by BearCat49:
In general, newer, current generation systems are installed in utility rooms - not bathrooms.

Actually, they can be installed in many places even mounted on the outside wall of a house. Though I wouldn't recommend this in cold climates. They may not be located where the tank you're replacing is located. They need to be centrally located to minimize long runs.

JoW,
Electric ranges, clothes dryers and tank type water heaters run on 220 VAC. Electric tankless units do require a large circuit but it is generally something a modern service can handle.

Didn't say they couldn't be installed in other locations or wouldn't be installed in the best location possible to operate efficiently. That's why my comment was prefaced by the phrase, "in general".

In addition, if you read the thread prior to posting, you know that I was responding to comments about older generation models typically installed in bathrooms.

Bearcat think of it as an amplification not a correction. These are quite versatile though I'm not personally sold on them. My water use points are so spread out in our 2 story house that I'd definitely need a circulation pump to have one. The kind of pump you need for these is turned on for about 30 seconds before you turn on the tap to get the heater going and to send all the cold water in the lines back towards the water heater to get heated rather than down the drain. I have a circulation pump under my bathroom sink which is a good 75 feet of 1" pipe away from the water heater in the basement. I could run 5 gallons of water down the drain before I installed it. The kind I have is not appropriate for a tankless system.

I've read the thread by the way.

The post was clear and concise - no "amplification" was necessary. Funny that you didn't choose to amplify posts referring to older generation systems.

I could amplify your post but I'll be courteous and let your misinformation stand.

If you're interested in reading here are a few links and articles on the subject.

First is an article that is several years old from Consumer Reports on installing tankless water heaters. That you might find useful if trying to decide on tank v tankless. I doubt the economics have shifted much since the article was written 4 years ago.

http://www.consumerreports.org...water-heaters-ov.htm

Tankless water heaters
They're efficient but not necessarily economical


VIDEO:
Tankless water heaters
All videos
Heating water accounts for up to 30 percent of the average home's energy budget. Some makers of gas-fired tankless water heaters claim their products can cut your energy costs up to half over regular storage heaters. So is it time to switch?

Probably not. Gas tankless water heaters, which use high-powered burners to quickly heat water as it runs through a heat exchanger, were 22 percent more energy efficient on average than the gas-fired storage-tank models in our tests. That translates into a savings of around $70 to $80 per year, based on 2008 national energy costs. But because they cost much more than storage water heaters, it can take up to 22 years to break even—longer than the 20-year life of many models. Moreover, our online poll of 1,200 readers revealed wide variations in installation costs, energy savings, and satisfaction.

With the help of an outside lab, we pitted Takagi and Noritz gas-fired tankless water heaters against three storage water heaters. We didn't test electric tankless heaters because many can't deliver hot water fast enough to replace a conventional water heater if ground­water is cold. Even in areas with warm groundwater, most homeowners would need to upgrade their electrical service to power a whole-house tankless model.

Our tests simulated daily use of 76 to 78 gallons of hot water. That's the equivalent of taking three showers, washing one laun­dry load, running the dishwasher once (six cycles), and turning on the faucet nine times, for a total of 19 draws. While that's considered heavy use compared with the standard Department of Energy test, we think it more accurately represents an average family's habits. We also ran more than 45,000 gallons of very hard water through a tanked model and a Rinnai tankless model to simulate about 11 years of regular use.

Here's what else we found:

Water runs hot and cold
Manufacturers of tankless water heaters are fond of touting their products' ability to provide an endless amount of hot water. But inconsistent water temperatures were a common complaint among our poll respondents. When you turn on the faucet, tankless models feed in some cold water to gauge how big a temperature rise is needed. If there's cool water lingering in your pipes, you'll receive a momentary "cold-water sandwich" between the old and new hot water. And a tankless water heater's burner might not ignite when you try to get just a trickle of hot water for, say, shaving.

Nor do tankless water heaters deliver hot water instantaneously. It takes time to heat the water to the target temperature, and just like storage water heaters, any cold water in the pipes needs to be pushed out. And tankless models' electric controls mean you'll also lose hot water during a power outage.

Up-front costs are high
The tankless water heaters we tested cost $800 to $1,150, compared with $300 to $480 for the regular storage-tank types. Tankless models need electrical outlets for their fan and electronics, upgraded gas pipes, and a new ventilation system. That can bring average installation costs to $1,200, compared with $300 for storage-tank models.

Tankless units might need more care
During our long-term testing, an indicator on the tankless model warned of scale buildup. We paid $334 for special valves and a plumber to flush out the water heater with vinegar. Many industry pros recommend that tankless models be serviced once a year by a qualified technician. Calcium buildup can decrease efficiency, restrict water flow, and damage tankless models. Experts suggest installing a water softener if your water hardness is above 11 grains per gallon. Ignoring this advice can shorten your warranty.

Efficient storage models are pricey
We also tested the $1,400 Vertex, a high-efficiency storage water heater by A.O. Smith. The manufacturer claims its installation costs are similar to a regular storage model. But its high cost offsets much of the roughly $70 per year the Vertex will save you. Instead, we recommend buying a conventional storage water heater with a 9- or 12-year warranty. In previous tests, we found that those models generally had thicker insulation, bigger burners or larger heating elements, and better corrosion-fighting metal rods called anodes.


And a link to the Energy Department website on the subject: http://energy.gov/energysaver/...d-type-water-heaters

And a buying guide on them: http://www.tanklesswaterheaterguide.com/

And a tutorial on them: http://www.tankless101.com/

An article talking about circulation pumps and standby loss. In my house I have option 2 a retrofit-by-pass system located in my master bathroom. For tankless systems option 3 is preferred. These are helpful when the unit is far away from the point of use. The entire article is worth reading and can be found at the link.

http://www.bcpsi.com/water_heaters.nxg

HOT WATER RECIRCULATION SYSTEMS

Homes that have a long run from the water heater to the farthest fixtures will experience a long wait for hot water. You turn on the faucet, wait for a minute, and the water is still running cold. Tighter restrictions on flow rates and “greener” fixtures make this problem even more annoying. It wastes water, energy, and is inconvenient.The solution to this problem is a hot water recirculation system. These systems overcome the problem by circulating hot water so it is available in the nearby supply pipes. The system is designed to provide hot water at the most distant fixture and every fixture in series or close to the main line. There are three basic types of recirculation systems:

1) Traditional: This system consists of an extra “return” pipe that allows water from the farthest fixture to be returned to the water heater. A pump is located near the water heater and when it is on water is pushed out of the heater and back through the return pipe. The pump can be outfitted with timers and thermostats to keep the running time down to a minimum.

2) Retrofit-By-Pass: This system utilizes the cold water line as the return line to the water heater. A pump (generally located on the top of the water heater) is used to create a slight pressure differential that allows the cool water in the hot water supply line to by-pass into the cold supply line. This is accomplished through a thermostatically controlled valve that is mounted at the furthest fixture from the water heater. The pump is equipped with a timer that allows the system to run whenever desired.

3) Demand: This system is similar to the retrofit system above because it also utilizes the cold water line as the return line to the water heater. The similarity ends there because this system requires that the pump be mounted at the farthest fixture. When hot water is “demanded” a wireless remote is pressed that will activate the pump. The pump will run until hot water reaches the sensors and then it automatically shuts down. In lieu of a remote, motion sensors may also be used. If you have a tankless water heater this is the system that generally works the best.We are familiar with all of these systems whether you want one installed or need your existing system repaired. They all have their advantages and their drawbacks, which is why you need to consult with us before making a decision. Remember, there is no substitute for experience.