Tank vs tankless water heaters

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On Sunday, August 11, 2013 11:45:39 AM UTC-4, dadiOH wrote:

It's indeed questionable how much, if anything, you save by going up the technology curve with water heaters. As I stated in another post, every time I look at this, it does not appear worth it to me to get a more advanced, energy efficient water heater, eg power vent, tankless, etc.
In the other post I gave numbers for two GE 40 gal water heaters at HD. One a typical basic water heater, the other a higher efficiency power vent. It was about $500 more upfront cost for the more efficient one. Using DOE numbers, it would take 14 years to recover the extra upfront cost. And that doesn't factor in the time value of money. Taking that into account, you'd likely never recover the money. It also doesn't take into account that the std water heater uses a chimney, the power vent is a direct vent type and it also requires AC. So, if you're going from regular to power vent, the install cost difference could add hundreds more to the price. Then instead of 14 years, it could take 20+ years to get your money back. Well beyond the expected life of the unit.
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I suspect that the numbers will improve over time, but I agree, right now it doesn't seem to make too much sense to trade in a technology that's tried and true for something quite a bit more complex. Especially if the payoff's a long, long time away. Or never.

I'm never surprised that such calculations (by the vendor) are optimized quite agressively and leave out the things you've mentioned that could easily push the cost very much higher. I'd only go for a tankless if I didn 't have to heavy up the gas feed AND I really needed the space that a standard tank heater takes up.
Manufacturers often live in a dream world. Take MS. They marketed the Zune player to compete with the iPod. It was a disaster. Having learning nothing from that they created the Surface RT tablet to compete with the iPad and recently took a $900 million write-down of unsold inventories of that product. The SRT tablet is a remarkable tale of groupthink gone wild.
The saddest part about MS's tablet offering is that 10 years ago they were leaders in the nascent tablet world but their commitment to desktop PC's caused them to abandon that lead, and perhaps the eventual leadership of the industry. People repeatedly say things on surveys that sound like this: "If Microsoft expects us to throw over working PC's every three years, I am going to try an Apple product - it couldn't be any worse!" The number of times they've had to extend support for XP pretty much proves people are damn tired of upgrading tools they know how to use for a new OS that's based on a totally different paradigm.
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Bobby G.



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So true and a reminder that everyone here has a slightly different set of circumstances. You're making me think about putting a solar water heater with a gravity-feed holding system. In Scotland they've hollowed out a mountain to store water at night to store excess generating capacity of the grid. The reservoir is pumped full at night and generates extra power during peak loads by letting the water flow past a turbine.
http://www.theregister.co.uk/Print/2013/07/23/reg_man_delves_deep_to_find_the_power/

Jeez. I've always thought it's better to lose power in the winter because (like a number of adventure films have shown) there's lots of furniture and books to burn for heat if push comes to shove. It's hard to keep cool in some areas without power, and that was one reason I was adamant about not moving us to Arizona for retirement. It was like Buffalo in reverse. That area got so cold you could get trapped in a blizzard far too easily and end up dead. Same with Arizona. What do you expect from a part of the country with a place named "Death Valley?"
It's the (very) temperate zone for me! (-:
(No hate mail from the SW or NE lovers, please!)
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Bobby G.



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What everyone seems to miss, is that there are three types of tank gas water heaters. 1 - Conventional vented water heater, cheap with little efficiency. 2 - Power vented water heater, mid-priced, needs no chimney, little gain in efficiency. 3 - Condensing water heater, highest price, needs no chimney, very high efficiency.
I have a condensing water heater, it can heat an ice cold tank in 10 minutes, you cannot use the water faster than it can make it, it just sips gas and dropped my gas bill by $20.00 per month over my old conventional heater.
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On Friday, August 9, 2013 12:17:01 PM UTC-4, EXT wrote:

Virtually all the condensing water heaters are tankless, no? I just googled and looks like Rheem announced they were making the world's first tank type condensing unit. And it brags about an energy factor of .80 I'm still betting that it takes one hell of a long time to recover the cost difference.
A cheapo regular tank type GE water heater that costs $347 at HD has an energy factor of .59 and an estimated annual operating cost of $309. Looking at the GE power vent model, it cost $845, has an EF of .67 and costs an estimated $272 a year to operate. So, it would take 14 years to recover the extra money it costs for the more energy efficient one. And that ignores the time value of money, the fact that it may not last 14 years, etc. Everytime I look at water heaters I come to the same conclusion. The higher efficiency, much higher priced units, don't have an economic advantage. At least not in my world. Apparently not in the EPA's world either, because those energy factor numbers and costs to operate are their numbers.
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I got estimates from at least 3 reputable licensed plumbers for both. Estimates for a tank-type were pretty consistent. Estimates for tankless were all over the place, so that alone convinced me to stick with something that everyone knows how to install.
Even with moving it from inside the house to the garage and installing a new roof vent, the total cost was 1/3 that of a whole-house tankless type. And it just plugs into a standard 110 receptacle. Installation was simple and easy to check. Energy rebates for both types had little effect on any of the systems we were looking at.
One plus for whole-house tankless would be it can be mounted on an outside wall and free up room inside if that's important. But then you have all the exterior wall penetrations.
Whole-house tankless would also have required extending gas piping and new 220V wiring. I'm not a big fan of running 220V when there is an alternative. Plus this house has a 50 year old breaker box & wiring which would have required upgrading.
Tank type here is gas, which is a lot cheaper to use than electric around here.
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On Saturday, August 10, 2013 4:40:55 AM UTC-4, Guv Bob wrote:

re all over the place, so that alone convinced me to stick with something t hat everyone knows how to install.

And it just plugs into a standard 110 receptacle. Installation was simple and easy to check. Energy rebates for both types had little effect on any of the systems we were looking at.

the exterior wall penetrations.

ive. Plus this house has a 50 year old breaker box & wiring which would ha ve required upgrading.

I don't see why a gas tankless would need 220V. Nothing there that should require 220. What does it have? Some electronics, an ignitor, maybe a draft inducer blower?
But the rest of your experience is consistent with what we've heard here before. I think for the right application, tankless can make sense, but it usually doesn't make sense for a replacement of an existing gas tank unit. And if it's going into new construction, that can greatly reduce the cost of the install.

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Electric controlled natural gas tankless won't work during power cuts. When ice storm 2003 hit, I was out of power, four days. A hot shower (old style tanked natural gas WH) sure made life more comfortable.
. Christopher A. Young Learn about Jesus www.lds.org .
On 8/10/2013 9:24 AM, snipped-for-privacy@optonline.net wrote:

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during power outages here people have run a garden hose thru the home with a slow flow of hot water to provide enough warmth to prevent freezing.....
tankless are just a bad idea all around. espically if you have teenagers, they can get a endless hot shower that runs up all the utility bills..
endless use of gas to heat the water, water and sewage, and even electric to run the tankless... bigger bills all around
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On 8/10/2013 9:30 AM, bob haller wrote:

Me and my late friend GB installed a Bosch natural gas tankless in a beauty shop. The Bosch has a paddle wheel generator the runs the electronic igniter and controls. It's the only type of tankless NG water heater I would purchase for myself because it will work when the power is out. It supplied plenty of hot water for the beauty shop. ^_^
TDD
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Well they can, but they also can with other types of water heaters too. With my old tankless oil fired boiler you could shower forever and my daughter tried to. Very often I'd go in and turn the boiler off to get her out of the shower.
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<stuff snipped>

That's pretty funny (as a guy who didn't have to pay the bill can say!).

Meanie! (-:
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I heard that one on the radio. during ice storm 2003. Clever idea, and does some good.
. Christopher A. Young Learn about Jesus www.lds.org .
On 8/10/2013 10:30 AM, bob haller wrote:

garden hose thru the home with a slow flow of
hot water to provide enough warmth to prevent
freezing.....

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Come to think of it, Bob, you were the one that gave me the idea to do that and it does, indeed work quite nicely. A bit of a waste of water, but a flood from cracked pipes would be worse.

My neighbor was sure something in the street was leaking and causing her water bill to soar. It was her daughter and brood letting the water flow, flow and flow. The kids turned on the backyard hose and left it going all day. You'd be surprised at how much water can flow from a dinky little garden hose.
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All tankless with power vent require line voltage to operate.... to run the blower....
I dont like running out of hot water, when we moved here the house had a 30 gallon tank... i froze getting a shower...
it currently has a 75 gallon 75,000 BTU tank. i never run out of hot water....:)
75 gallon is really over kill but they stopped making 50 gallon 75,000 BTU heaters. the 50 gallon fit the space better....
the bigger tank cost more to purchase but lasts far beyond it warranty, probably because thermal shock is less....
tankless clog and they sell cleaning kits to run acid thru it to remove sediment and tankless are pretty complicated, unlike regular tanks.
lets say a regular tank heater costs 600 bucks and has a average life expectancy of 10 years the cost is 60 bucks a year or the cost of a single decent candy bar a week, today perhaps $1.30 each...
thats super affordable and regular tanks rarely cause a problem till their end of life leak......
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a word of warning about electric tankless. they draw so much power you will likely need a 250 amp service just for heating water, and a second service main for everything else.
upgrading electric service might require a utilty company upgrade. possibly a new transormer and new local service lines....
upgrades for gas tankless can be pricey too. might need a new main gas line from the street, a bigger meter with large line directly to the tankless..
my best friend ran into a similiar problem. he converted both vehicles to CNG, and gasoline. he did this back in 1972 during the first oil shortage. and installed a large compressor to fill the tanks..
he talked to the gas company, and found they would charge him a fortune for a higher flow line at his home, for filling the vehicles tanks.....
so he slowed the big compressor way back to limit the gas flow, and installed some large tanks for a quick fill ability....
he happens to live in a older low pressure gas area, with no regulators at the meter.
get this if he ran the compressor at normal speed he could of pulled vacuumn on the neighborhood gas line, and inverted the pilot lights. possibly causing a neighborhood explosion
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