40 gal just not enough: Replacing water heater for 2400 sq home. Family of 2 adults + 2 children

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wrote:

Depending on your local rate it could be easily 80% more efficent, mine was about 75% cheaper converting from electric tank to Ng tankless. Then again some have cheap hydro and expensive fossile fuel, and savings could be Zero. Each person has their own unique set of costs, for some tankless is best, for some that would need large tankless and major gas work tankless are not worth it.
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electric almost always costs more than natural gas to heat water
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On Tue, 8 Apr 2008 07:03:41 -0700 (PDT), ransley

Hi Mark,
We're really speaking of two separate things: efficiency and cost-effectiveness based upon fuel choice and my comments pertain to the former. The poster claimed a "tankless is 80% more efficient than an electric tank" and this statement is categorically false.
As noted above, the standby losses of an electric water heater with an EF of 0.93 or better are less than 1 kWh/day; at $0.10 per kWh, less than $3.00 per month and during the winter months the net out-of-pocket expense would be lower if the tank is located inside a conditioned space (effectively nil if the home is electrically heated and potentially net positive if heated with oil now that fuel oil in many parts of North America is more expensive than electric resistance).
Cheers, Paul
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thought we needed watr heatr and researched tankless but was afraid we'd lose our on demand feature and waitng 4 hot water would b an issue..mayb ok 4 auxiliary hot water...good luck..sherry
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Thomas G. Marshall wrote:

run out and it stops running just as soon as you cut off the faucet. I know because I had one.
--
Blattus Slafaly ? 3 :) 7/8

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On 04/07/08 01:24 pm Thomas G. Marshall wrote:

ISTR that the standard capacity in Australia was 60 gallons, with 80 gallons as a common upgrade -- and remember that these are "Real gallons," each consisting of eight 20-ounce pints. The one already in the house we bought in the US Midwest, however, is 50 (mini-)gallons.
I don't know how the various brands rate here in the USA, but Rheem was common in Australia. When we built our house in Australia, however, we used a local (I mean really local, not marketed outside that State, AFAIK) brand that had a 25-yr warranty. One day I was wandering through a shopping mall and got accosted by the salesdroid at a Rheem booth who asked me how old my water heater was; when I told him "12 years," he said, "Oh, so you'll be needing a new one soon"; when I told him the brand I had, he said, "Oh, then you won't be needing a new one for a long time yet." IOW, widely advertised brands aren't always the best.
Perce
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Before concluding that 40gallons is the problem, I'd check the shower heads and flow rates. You may find that reducing the shower flow a bit means you will have enough hot water from a 40 and save energy too. Also, it's possible the existing one has some serious problems. If it's full of sediment, has a broken dip tube, etc, it may not be performing anywhere near what a new one is capable of.
Check the first hour rating on the ones you are considering. That'a a good indicator of how much water they can supply in typical high demand hour.
If you do decide to go larger, I'd think a 50 with a good first hour rating would probably be enough for most families of 4.
As others have pointed out, you can also consider tankless. Main issues there are unit and installation cost, which can be higher depending on existing gas lines. The TL needs a much larger gas supply.
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regular 40 gallon hot water tank BTU vary anywhere from 34,000 btu to 75,000 btu. the higher the BTU the better.
Because we ran out occasionally we went from a 34,000 BTU 40 gallon tank to a 75,000 BTU 50 gallon tank. I wanted a 75 gallon tank but it wouldnt fit the available space between toilet and furnace.
Tankless tends to be a hot topic here........ from inadquate heat, cool showers if you live in areas that freeze in the winter, no hot water at all in a power failure, if the tankless uses line voltage to operate, no hot water with valve just open a little, super expensive install, needing new gas line and occasionally a new meter. teenagers given unlimited hot water might live in the shower. expensive service, tankless are complex and require occasional service, standby losses in current tanks is actually low, and stanby losses help heat your home in the winter, so most of the heat isnt really lost. life is full of sytandby losses, tv, cable boxes clocks etc etc. anything that draws power when not in use is a standby loss......
your old tank is probably full of sludge decreasing its hot water ability.
a new tankless will cost a fortune.......... 3 to 4 times a standard tank which is highly reliable.
so lets talk tanks
upgrade from your old 40 gallon probably 40,000 btu to a 75 or 80 gallon 75,000 btu will likely give you about 4 times or more your current hot water capacity. and in its life probably never need service
you double the gallon capacity and double the burners BTU rating, roughly 4 times the hot water.
no more cold showers:)
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Here we go again the same missinformation, with 90-100f temp rise offered you cant have a cold shower, I cant shower at over 106f but my unit takes 35f water and heats it to 125 if I was to be wastefull.
Mine has battery ignition and regular vent-No A.C. But I have a generator for my home for heat.
It took me 5 hrs to install, but I guess thats "super expensive" for you. I put in 3/4 gas but that was only 1 hr work, again easy and cheap, my meter is original.
Tankless require no "service" but tanks are supposed to be flushed every year.
20% of your loss is waste-up the chimney and out, of no benefit to anyone but your gas supplier since true overall efficency is near 50-60% in " Energy Factor" proven ratings
I paid about 500$ for a Bosch 117000btu unit, I get a FOUR year payback, I hardly see the 3-4x cost of waste, I see I am saving money
Tank, loose efficency every year due yo scale settling over the burner, just as my last tank had over a foot of scale at the bottom, its efficency was probably reduced 20-40%, tankless dont do that, and its easy to pour lime away through mine. You cant do that with a tank.
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.

you said above
"Tankless require no "service" but tanks are supposed to be flushed every year"
then talk of pouring lime away thru yours
"tankless dont do that, and its easy to pour lime away through mine. ""
frankly draing a little bit of water out of the bottom drain valve is way easier than taking the plumbing apart to pour in lime away, which isnt cheap, and then flush it out somehow.
plus you always talk of 20% going up the chimney as standby loss but refuse to supply a link to verify that:(
people who go tankless have spent so much money they will have to convince themselves it was a good move........
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Kind of like the boys with the high dollar K$N filters on their trucks. .... They'll always tell you they run better when they know good and well it made no difference whatsoever...
s
people who go tankless have spent so much money they will have to convince themselves it was a good move........
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I don't think that's fair. Ransley says he's actually bought one for $500 and installed it himself relatively easy. And he's happy with the results. I think his opinion is worth more than most here most of whom don't have one and just sling mud. Especially those that continue to spout misleading information, like "The heat loss from a tank unit helps heat your home in the winter." It's been pointed out repeatidly that much of the waste heat in a gas tank unit goes up the flue. And the heat that escapes the sides of the tank only helps heat the house if it happens to be in the living space, which isn't where most are located. And then, in summer, the heat is still added to the house and if you have AC as most do, then you're paying to remove that heat. Yet, this same sad misinformation continues.
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On Tue, 8 Apr 2008 08:26:00 -0700 (PDT), snipped-for-privacy@optonline.net wrote:

The OP has an electric water heater and electric units do not have stack related losses. The only loss is through the tank wall and these losses are less than 1 kWh per day if the tank has an EF of 0.93 or better (the new minimum standard is 0.91).
Secondly, if the tank is located inside a conditioned space any heat loss through the wall *will* offset a portion of the home's space heating demand. If the home is electrically heated the net loss is effectively zero during the heating season and for those who heat with oil, the losses could result in a net positive gain now that residential fuel oil is more expensive than electricity in many parts of the country.
With respect to air conditioning, a central air unit with a SEER of 10 would eliminate 2.94 kWh of heat for every 1.0 kWh consumed (the ratio is 3.8 kWh to 1 for a 13 SEER unit). Thus, the additional a/c burden for a 10 SEER model if tank losses are 0.91 kWh/day would be less than 10 kWh/month.
Cheers, Paul
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wrote:

No he doesn't. OP wrote: "Ok, our 40 gal gas water heater is failing. About 10 years old, which I hear is ok."

Most of the water heat inefficiency goes up the flue, so do most of the dollars. It's an odd argument to state that putting a heater (waste heat from the water heater) in a location that you don't need it, is a smart move. Maybe we should all go back to the huge ass furnaces under the house with one central floor grate to heat the home. Then none of the inefficiency is lost...unfortunately most of the comfort is.
R
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wrote:

Yes, but that has nothing to do with much of the mis-information and slams directed against tankless units. All I'm saying is Ransley actually has one, paid $500 for it, installed it without too much effort and says it works well for him. That's some actual data, instead of speculation.
Also, the vast majority of tankless are not going to be compared to electric water heaters, but instead to gas ones. That's because almost everywhere, it's cheaper to heat water with gas than electric. So, someone looking for a water heater with gas available, isn't going to be looking at electric and then you do have the heat loss via flue.

Yes, that's true, but as I already pointed out:
1 - At least one regular poster here continually mentions the winter benefit of heat loss without regard to where the water heater is located and totally ignores the AC impact in the summer.
2 - Most water heaters are not located in a conditioned space.
3 - In the grand scheme of things, this whole heat loss benefit is a nit.
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most water heaters are in basements, heat rises, so standby losses help heat your home. or in a closet on a living floor, again standby loss heats its suroundings, thats where you live.
again please post a link that says 20% go up the chimney........ please a link....... please........ all i see is someone stating it must be....
since the cost beween a regular tank and a tankless can easily be a grand, that $ could be spent for added insulation and weatherstripping
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Take a look at <http://www.aceee.org/consumerguide/waterheating.htm , in particular the life-cycle costs comparison. This shows a typical gas tank water heater has an energy factor of 0.60, and a typical gas tankless has an energy factor of 0.80. The difference of 20% represents the standby losses. Prior computations suggest that of those standby losses, 7% represents the loss through the tank insulation, and 13% represents the loss through the gas flue.
Cheers, Wayne
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Hey Hallerb, here it is, read and learn.
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look all along you have been posting 20% up flue but your own link says.......
", 7% represents the loss through the tank

since stanby helps heat your home in the winter, only 13% is actually lost.
does your tankless have a pilot, if so the government says your saving nothing........ this is highly likely since you stated your tankless works in a power failure
if your home uses a lot of water the standby time is less, and your tankless saves little, according to the government link here
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Gee mine was 500 with TAX, what a missinformed negative puts you are.
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