Tank less water heater

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Can anyone give me some advice about tank less water heaters? Thx!
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They're very small. They only come on when you open a hot water faucet. They use lots of electricity or gas while they're working to keep up with the demand, but none when there is no hot water flowing. The benefit is that your not paying to heat and store a big tank of hot water. Sizeable units are expensive to purchase and you need an adequate electric service or gas service to operate them
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RBM wrote:

Thanks. I am looking for someone who has or had one and can recommend a brand name. Already did my search on the Internet and know everything the websites are suggesting, this is why I need a person who has one, and that is not to say that your advice wasn't sufficient because it was :)
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On 3/30/2008 2:04 PM nospam spake thus:

>

>>

Yes; Takagi. I just helped install one (I did the wiring, a real plumber did the rest). This apparently is *the* state-of-the-art tankless heater currently. The model we installed is pretty kewl, in that it is made for exterior installation and requires no venting (it vents from a small grille near the top of the unit). Very efficient, compact (surprisingly small) and well-made.
This one also has electronic ignition, so uses no gas at all when not needed (unlike older ones with pilot lights). The only downside to this seems to be that it will not work during a power failure; there seems to be no way to manually light it.
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If you can tell us why you are asking, maybe we can provide better advice.
--
Joseph Meehan

Dia \'s Muire duit
  Click to see the full signature.
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What kind of advice?
Do they work?! Yes.
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Advice? Ya, don't bother. You'll never get the water hot enough (especially in the winter) to wash dishes properly. Even hot enough for a proper shower is questionable. And don't even ask about the flow rates.
s

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gas or electric? if electric just forget it, unless your willing to upgrade your main service to 200 amps just for heating water. can cost thousands, really.
gas? delay from valve open to hot water arrives, heater must detect water use then turn on burner. you will waste water.
with low flow valve open a little to wash dishes may not be enough to trip on burner, cold water a result.
if your tankless needs line voltage to operate a power outage means no hot water at all. a standard tank still has a tank full to give, for say 2 quick showers.
tankess warranty is no longer than a regular tank. you need qualified service people they are complex. standard tanks are highly reliable till they leak, at which point you replace them...... nearly no service needed
if you live in a area that gets cold, incoming cold water can cause tankless troubles when water gets really cold. around here it bottoms at about 40 degrees.
the tankless savings are bogus, regular tanks standby losses are really low, take a look at the energy guide. in the lifetime of a tankless you will save little because of the large up front cost. oversize gas line, high capacity flue/
in the winter standby losses help heat your home
endless hot water can get some folks to live in the shower, driving up water and gas use........ teenagers are the worst.
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Here again more bad info, the savings are there and tank true energy rating is the Energy Factor, its amazing how everyone just " forgets" this rating. I own one, they work fine and save you money.
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20% of the Standby loss goes up the uninsulated center part of the tank, up the chimney, and does not provide additional heat to your home, thats why 50-60 is the true Energy Factor rating, or what you get out of every dollar you put in.
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please cite this claim..... of 20% up the flue.........
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I don't have a citation, but it is easy to derive this number. A typical 80% combustion efficient gas tank water heater has an energy factor of 0.60. The energy factor of 0.60 means that temperature rise of the hot water delivered during the standard 24 hour test period represents 60% of the theoretical heat content of the natural gas burned during that period. So 40% of that theoretical heat content is lost to the user.
Since the combustion efficiency of the burner is 80%, 20% is lost as soon as the fuel is burned. The other 20% represents standby losses. Most of this is due to air being warmed as it rises through the flue. For example, a good electric tank water heater might have an energy factor of 0.93, and such a tank has no flue. So through the outside of such a tank, 7% of the theoretical heat content of the electricity used is lost to the user. Thus we might infer that for our gas tank water heater, likewise 7% is lost though the outside, meaning 13% is lost up the flue.
These numbers are rough and depend alot on the amount of insulation on the outside of the tank. But obviously there can be no insulation along flue or heat exchanger, so that is a large source of standby losses.
Cheers, Wayne
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Look up Energy Factor ratings on WH, Your burners are about 80-83% efficent on non condensing units but Energy Factor which is the true Energy rating taking into account heat loss are on average 60 for Hw tanks. The center is uninsulated and goes out the chimney. Foam insulation on tanks are very good and heat loss through the insulation is minimal, the real waste is up the center and out the chimney. Tankless Energy factor is the burner efficency rating mine is 82, no tank does that well except electric. so compare all 3 tankless, electric and gas , the difference in electric to gas tank is the center flue and it adds to a 20% - + loss.
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now is what your saying your tankless is 82% efficent
as compared to a regular tanks 60%??????
so your saving 20% a year on heating your water?
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Replacing a 0.60 EF (Energy Factor) tank with a 0.80 EF tankless should reduce your usage by 25% (1 - 0.6/0.8). That assumes your usage pattern matches the standard usage pattern of the the EF test. If your usage is less than the standard, your savings will be higher (as the standby losses will be comparatively greater), while if your usage is greater than the standard, your savings will be less.
Wayne
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Agreed.

One or two seconds.

Only at very low flow.

Truth. But there are a number that don't need line voltage.

Dead flat false. We have two hot water heaters in the house. We replaced one with a tankless. Our summer gas bill promptly halved (both dollars and volume). The heater we replaced services the kitchen and laundry where the hot water use is fairly low, so standby losses are a large percentage of the cost. I figured a five year payback, much less with gas cost up.

And raise your air conditioning bill in the summer. Or do nothing if the heater is in unconditioned space.

When our twenty something daughter moved out, both the gas and water bills took a significant drop. The tank water heater has enough recovery to feed a low flow shower head all day. Sigh.
-- Doug
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Mine operates sucessfully 2 years with the original 2 D cells for the Battery ignition - No AC Needed, no power vent. Its amazing how many Lian Miss informed ASSes will put down a Tankless since the either they " dont sellem" "Dontservicem" and what ever Biased, BS, LIAN, reasons I can`t figure. What Bull Shit these Crap Heads, Shit Heads, are, yes full of Bull Shit......Obviously TANK sales employees or orther idiots, associated with TANKs..........
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And of course more bad advise from someone who does not own one, has not used one properly installed, but seems to think he is qualified in giving advise, which happens to be total BS.
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How far back does your newsreader go? There was a long thread on this under:
Newsgroups: alt.home.repair,alt.hvac Subject: Most efficient water heater? Date: Sun, 16 Mar 2008 20:27:22 -0400
Don <www.donwiss.com> (e-mail link at home page bottom).
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How far back does your newsreader go? There was a long thread on this

I suggest we disband the newsgroup. Everything has been discussed, and is available at Google. Therefore this newsgroup serves no further purpose.
Yer welcome.
Steve
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