Tankless Hot Water Heaters

[Gary KW4Z]

My plans are to specify a (Gas) Tankless Hot Water Heater in our new home for my wife and myself. I'm thinking about actualy including two of them, one for bathrooms and one for Kitchen and Laundry demands but not sure on the total number to have yet.

I've looked at Takagi, Rinnai, Noritz, Paloma, Bosch, and Rheem. Like everything else most familiarity with Tankless hot water heaters comes from advertisements on the radio and TV and of those Rinnai seems to put the most money in that area.

Of you who have a tankless hot water heater which ones are the most trouble free and which would you recommend? Thanks, in advance, for your help and input.

[DerbyDad03]

Along with reading the info you will get in response to your current question in this group, may I suggest you perform a Google Groups search on the subject. This question has been discused in alt.home.repair, alt.building.construction, misc.consumers.house, misc.consumers.frugal-living and many other groups. There is a lot of information from various sources available in these groups.

Go to

and enter your query.

Good Luck!

Gary KW4Z wrote:

[hallerb]

your far better off to go with 2 standard larger tanks.

are you trying to get endlkess hot water? or more concerned with saving a little money on energy?

2 tankless will require large gas service and remember a power failure probably means no hot water

standard tanks even forced thru wall vents have enough hot water stored for a couple showers

[NuWaveDave]

At what elevation are you? It's been recommended to me that a tankless water heater loses considerable efficiency at higher altitudes.

[Rich]

I have the Bosch and would recommend it. It has a built in ignition system that runs by the water turning a wheel to create the spark so it will even work when the electric fails. I bought the smaller 1 use at a time unit but for a family of 3 or more I would recommend the larger unit. But for me the

1 use is just fine. It installed easily (by myself) and has worked flawlessly for 3 months that I have had it.

Rich

[# Fred #]

If I understand correctly, one correctly sized tankless could supply enough hot water for all the appliances plus showers and baths at the same time. As for the electric outages, a UPS - uninterruptible power supply, just for the controls - should take care of that.

My concern is the reliability, and I hear some of the tankless heaters are not good. I've been using hot water dispensers for years and those tanks goes out about 5 years (something always goes out in about 5 years) and I just couldn't justify replacing a tankless every 5 or even 10 years. Hot water heater: $500, Tankless: $3,000. Tankless has to save a lot of energy to justify the extra cost. Anyone know what the payback is for tankless?

[Bob Dozier]

I had a Noritz N-069M

in my newly constructed home of about 2500 sqft with 3 1/2 baths. I love it! With no circulation pump at all, most hot water locations get hot water within a minute. The only real wait time for hot water is the master shower, it takes about 2 minutes. But the jetted tub just a few feet from the master shower gets hot water in about 30 seconds. More water volume to the tub vs. the shower head really cranks up the heater. I'm in west Texas with very hard water - it is highly recommended that you have a water softner in place in hard water conditions.

Give Noritz a pre-sales call, they were very helpful when I spoke to them. I considered zoning two units, but the sales guy conviced me the N-069M would be sufficient, but suggested that if you ever needed to, you could simply add a second unit. They are designed to work in tandem with a connector cable.

...Bob

[kennybs]

1) Demand- 2 shower heads, 8 body washers in one shower and trying to fill a whirlpool ain't going to cut it. 2) Location- some one in the northern part of the country where service water comes in @ 40 degrees 4-6 months out of the year is a lot different from someone in the south where service water is seldom under 70 degrees.

Run the numbers and you'll be fine, don't believe what someone tells you.

kenny b

[hallerb]

the payback period exceeds the expected life of the unit, say 10 years thats the longest warranty on a tankless. any companies locally for service?

so for 500 bucks you can get a standard tank with a 12 year warranty. you would have to save more than 2500 bucks before saving a dime in energy.:( check the energy guide labels of tanks thats probably the entire operating cost of a regular tank. mine says 250 bucks a year, times 10 years wheres the savings?

worse assuming your tank in in a heated part of the home the wasted energy in the heating season helps heat your home so its not wasted at all....... for the heating season. true its a loser for AC:(

new regular tanks are actually very efficent, you can get higfher btu models and larger tanks for never run out showers if you want. my 50 gallong 75,000 btu is near that, next tank will be 75 gallons, the 50 barely fit my existing space.... new furnace and more space.

think of another thing regular tanks are actually very reliable, other than spring a leak at end of life few have other troubles and are a bargain at 500 bucks.

you could likely save a few hundered a year in heating costs for your new home by doubling wall thickness and upgraded insulation...... at say 30 grand extra.

thats not a good deal either

[7 LAMPSTICKS 7 FEASTS 7 AGES O]

I don't even need to research to know: DON'T DO IT!

DerbyDad03 wrote:

[7 LAMPSTICKS 7 FEASTS 7 AGES O]

Three months?

You are kidding, aren't you?

Rich wrote:

[7 LAMPSTICKS 7 FEASTS 7 AGES O]

I know the payback: there is none.

# Fred # wrote:

[7 LAMPSTICKS 7 FEASTS 7 AGES O]

Yes, don't believe anything you hear.

Especially, don't believe this.

[e-mail] wrote:

[Dan_Musicant]

:I had a Noritz N-069M

in my newly :constructed :home of about 2500 sqft with 3 1/2 baths. I love it! With no circulation :pump :at all, most hot water locations get hot water within a minute. The only :real :wait time for hot water is the master shower, it takes about 2 minutes. But :the :jetted tub just a few feet from the master shower gets hot water in about 30 :seconds. :More water volume to the tub vs. the shower head really cranks up the :heater. :I'm in west Texas with very hard water - it is highly recommended that you :have :a water softner in place in hard water conditions. : :Give Noritz a pre-sales call, they were very helpful when I spoke to them. :I considered zoning two units, but the sales guy conviced me the N-069M :would be :sufficient, but suggested that if you ever needed to, you could simply add a :second unit. They are designed to work in tandem with a connector cable. : :...Bob

I have the same unit: Model N-069M-OD. It includes the remote control unit, which I use on a daily basis. I set the temperature somewhere between 110 and 120 depending on the weather when I'm going to take a shower and leave it at the lowest setting (100 degrees) for sink stuff (the rest of the time, except laundry). It cost $4000 including professional installation. It was installed by virtue of a city sponsored program, so it didn't cost me a cent. Part of why they did it was to solve the problem of how to route a vent for my dryer. Putting the water heater outside (which is how these are installed) resolved that problem. The water heater it replaced was a standard 40 gallon gas tank heater. I would never have had the idea of going tankless if the rep hadn't suggested it, and I wasn't going to refuse!

It works OK. I realize that at this point I'm on my own and I just hope it lasts a real long time because I don't presently like the idea of spending big bucks to fix or replace it.

I have a question about it myself, being how it deals with changes in demand. Obviously as flow of hot water increases or decreases the unit has to respond by decreasing or increasing the gas flame so that the water comes out at the appropriate temperature. I wonder if _overusing_ this will cause something to go bad. IOW, is it better to leave the flow when washing dishes in the sink at one flow rate or is it OK to keep changing the flow rate like I always did with my tank water heater.

The responses in this thread already taught me one thing: I think I need a UPS if I don't want to do without hot water in the event of a power failure. I guess it's no big deal, actually. Power failures, at least ones that last longer than a few seconds, are pretty rare here. Being without power would be a much bigger inconvenience than being without hot water. And I guess a UPS that would supply power for more than 1/2 hour or so is going to be costly. So's a generator.

Dan

[Rich]

And an earlier quote from this know it all:

I like the depth of knowledge that you expound on this thread but I do like your quoted statements! Now go away and bother some other group with your depth of knowledge please! Maybe alt.youdontknowwhatiknow.andicanproveit

Rich

[Bob Dozier]

Boy, created quite a stir of replies! I have some comments - for what they're worth....

- I've seen some posts about payout. Who cares about payout? If you can afford one, get one. In my opinion, it uses gas only when you turn on the hot water it will be hot as long as you wish. In a 3 1/2 bath house, when you have your kids and grandkids visiting, you will ALWAYS have hot water. If you deplete a 50 gal tank heater, it's gone and you will have to wait until the entire tank heats up, however long that takes - been there, done that, not pleasant.

- I've also seen some posts about price. Find a reputable dealer and/or plumber and you can get one for about half of the prices I've seen posted - installed! Just do an Ebay search for N-069M. Although you do need to have a plumber install the unit for warranty purposes, it really does not take rocket science to correctly size or install the unit. Just make sure you have the properly sized gas line supply as well.

I am very pleased with mine for over 6 months. I'll see how long it will last, but so far, I will install another one in the next house I build.

Again, just my 2 cents, no flames please. ...Bob

[# Fred #]

And I guess a UPS that would supply power for more than 1/2

Should be cheap as not much power required to control the gas fired unit. Go to any office or computer store and get one suitable for you unit - should be under $100. You need to replace the UPS battery once every few years.

[hallerb]

ahh check the current use of the tankless, if it uses a fan for exhaust you may need a really large UPS.

did you knpow there are commercial size regular hot water tanks, they can supply a hotel continiously so one home would be easy.. kinda pricey but available

[<josh]

My Takagi draws little enough current that if the power is out, I can run it off the pocket-sized power inverter I keep in my car. No added cost for that, I already had the inverter anyway.

[<josh]

My Takagi draws less than an amp maximum, and that's briefly while the blower is clearing the exhaust after the burner shuts off; most of the time it's much lower draw. Any decent UPS can handle 120W loads.