High efficiency, high recovery water heaters

I was going to get a whole-house tankless water heater, but changed my mind after reading various forums with lots of complaints about them. I like the idea of tankless, but want to wait till we move to a better house, where it will be easier to install one at every hot water faucet, and when the technology might improve such that you could use any amount of hot water from 1/10 GPM to 5 GPM, without any hot-cold sandwiches etc.

But I'm still shopping for a water heater. I want a high efficiency, high recovery one, but only 18 inches in diameter. That's a lot to ask, because it doesn't leave much room for insulation. It would probably have to have a special kind of insulation that provided more insulation per amount of thickness. I would be willing to pay about twice the price of a normal cheap water heater. Is there anything available that would provide what I want?

My present water heater is 18 inches in diameter, 40 gallons, but not very efficient. And it's old and has a leak. I want to hurry before the leak becomes serious. What would be my best bet in this situation?

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True high effeciency will cost you, its called a condensing unit. Why

18", I think you will be out of luck. AO Smith is a good brand with many different units up to maybe 85 EF. I have NG tankless and I have yet to hear anybody here complain that actualy has one or knew a dam about what they were talking about, complaining without knowing facts from actual use seems to be a way people justify their present 50% efficent tanks.
Reply to
ransley

Given the requirements of:

fast recovery high efficiency small size not cost sensitive

I'm left wondering, why not get a whole house tankless? But there is a lot we don't know, like what fuel options you have.

Reply to
trader4

Tankless water heaters have there place but like anything else they have limitations.

Ransley is a hardcore tankless cheerleader per his comment.....

about what they were talking about, complaining without knowing facts from actual use

Reply to
BobK207

I think the OP is willing to pay double the cost of a cheap tank type w/h......

can he get full whole house tankless for that price?

Honestly, a tankless install makes me a little nervous......all that up front cost & hassle plus heat exchanger life ???? and the distinct possibility of an under performing system. Maybe only in fringe use cases, but big initial bucks (& questionable payback) for the occasional lukewarm shower is something I'd like to avoid.

Maybe if I owned Ted Kaczynski's cabin & lived his previous life style but I don't see tankless working for me & my life.

cheers Bob

Reply to
BobK207

Thank your rep.

New construction is the best time for tankless. Trying to retro-fit with an unknowing plumber can be costly.

I'm a fan. One can even work on them and replace components as needed.

Reply to
Oren

I wouldn't recommend what I'm doing right now to my house as it is way expensive. I'm installing a 90% efficient Triangle Tube Prestige Solo 110 NG boiler. Along with an indirect water heater and over a half mile (no kidding) of ½" pex tubing for radiant heat. The pex was a pain to install. But the plumbing of the boiler, loops and pumps and other stuff is fun.

Waldo

Reply to
Waldo Point

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He can get a whole house tankless for $750 - $1000. I'd say that qualifies as a YES. And if you factor in the elimination of standby losses over time, it sounds like a potentially viable solution, depending on what fuel he has available.

And I'd say you're at least as biased against them as you claim Ransley is biased in favor of them. At least as Ransley says, he has one installed.

But we're not talking about your life style. We're talking about someone who:

Wants rapid recovery High efficiency Is willing to pay 2X the cost of a regular WH Has a small space reqtt, etc.

You see many conventional water heaters that fit that bill?

Reply to
trader4

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If the OPs current heater is electric he will be disappointed with any electric tankless........ nearly no one likes electric tankless.

and sure wouldnt like upgrading to 200 amp service just to heat water, plus normal 200 amp or whatever service for everything else.

that can easily cost thousands, and even then resul;ts may be marginal where incoming water is cold in winter, limited flow, etc.

tankless warranties are no longer than 10 years, heck you can get regular tanks with 12 year warranties.

regular tank heaters are simple, reliable, and pretty cheap to buy.

basic install and forget till it leaks.

while tankless require knowledgable techs, cleaning heater core removing sediment, and occasionl parts replacement.

heck even ransley talks of his personally repairing his tanless.

question, when the last time any of you serviced your regular tank type heater, most dont even drain water occasionally out the bottom to remove sediment.......

The condensing tank type water heaters cost about the same as a tankless, are as or more efficent, and dont have nagging troubles like no hot water with a faucet barely on....

ransley must have a fiancial stake in tankless heaters..........

Reply to
hallerb

The biggest problem with tankless water heaters is that DIY'ers and many plumbers don't bother with the size calculations. Sizing a tankless requires estimating usage and combining that with water pressure. The higher the water pressure, the larger the BTU's required to handle the same usage.

Also, remember that tankless water heaters are not energy efficient across the entire range of use. Sure you save the energy of storing a huge tank of water. But if you run a dishwasher, for example, that uses only a few gallons per cycle and you have high water pressure and high BTU's, you'll get very INEFFICIENT energy use for those few gallons. The burner will have to light up like crazy and then shut down fast after only a few gallons.

Tankless heaters are most efficient for bathing and that's where their energy calculations are made.

If they're sized right, they're a great improvement over atmospheric vented tank heaters.

Reply to
Rick-Meister

ransley wrote in news: snipped-for-privacy@q5g2000prf.googlegroups.com:

18" is what will fit where my present water heater is. We could make a little more room by moving some pipes, but not much.

I still might get a tankless. But we're leaning the other way right now.

Here are some of the concerns we have about tankless:

  1. We're concerned that it might not always give us as much hot water as we want. If washing machine and dishwasher are running, and someone is taking a shower, it could be stretched to its limit, and, if someone else turns on a hot water faucet, the shower might suddenly get cold bullets or whatever. If we connected two tankless together, it could be a problem for our NG supply, and two cost more than one.
  2. The supply of cold water to our house might not always be high enough pressure. We get the vague impression that our water pressure varies, possibly depending on usage by neighbors. It's probably not a problem, but it's one more minor worry.
  3. We're thinking of putting in new insulated hot water pipes, running through our access-only attic, to all of our hot water faucets etc. A tank water heater would keep those pipes partly warm, so we wouldn't have to wait as long for hot water after turning a faucet on.
  4. The tankless we want requires an electric outlet, for its ignition. It looks like we would have to do some wiring, because we don't see any electric outlet in the utility closet, but just conduit going to our furnace from the wall.
  5. If it turns out to have problems, the problems are most likely to be in our pipes or whatever, and not the fault of the manufacturer. Therefore, such problems would not be covered by the warranty. A lot of people regret getting a tankless for that very reason, and feel stuck with it, because it would cost them too much to replace it with a tank, having already spent their budget on the tankless.
  6. When such problems happen, the plumber often can't figure them out, and spends too much time on them, then starting thinking of that customer as a problem customer.
  7. If energy prices keep going up, I want to consier other options, such as solar etc., and/or maybe get a geothermal heat pump for heating and air conditioning, and get hot water from that same system. If I spend a lot on a tankless now, that reduces my budget for that.
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Anagram

My present top two choices are a 25-gallon 155-FHR from Bradford White vs a

40-gallon 50,000 BTU/H from Lochinvar.

The Bradford White is my favorite so far, but the Lochinvar is what seems to be available locally.

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Anagram

You wouldn't get cold bullets in the shower. The tankless would throttle down the output, so you'd lose pressure and flow everywhere, including the shower.

I think the minimum pressure is around 25 psi, do you fall below that?

And it is wasting energy while keeping those warm. If you are concerned about waiting for water on a long run, install a point-of-use, button activated hot water pump.

Cheers, Wayne

Reply to
Wayne Whitney

get the highest first hour rating that will physically fit the space......

Reply to
hallerb

Ransley is biased in favor of them.

Reply to
BobK207

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Yes mr hallerb, I do have a financial stake in my tankless, it gave me a 4 year payback over an electric tank, but I only paid under 500 and did the instal myself. At least this time tankless isnt getting beaten down completly improperly. But there is no tank to rust, its copper pipe designed to last 30 years, I ve done no maintenance on mine, but it is set up to be able to be flushed. But for a family, often a tank is best. For total Ng efficency no tank can match tankless by at least

10%, even condensing AO Smith units, And guess what, now AO Smith make tankless.
Reply to
ransley

Doesnt a dishwasher use alot of water, well if it was not efficent why am I getting a 4 yr payback, and why am I now paying 45$ for Ng where I now have a tank, where was just paying 7-9 in summer with the tankless, you have theories, and no numbers, I have numbers I dont need unproven theorys

Reply to
ransley

snipped-for-privacy@q5g2000prf.googlegroups.com:

And you will possibly need 1" gas line if the run is long. Shop Energy Factor or EF in your tank decision. EF is what it costs to heat the water, many cheap tanks are still 55-60 EF so only 55-60 cents of every dollar heats water, there are tanks, Condensing near 85 EF. I own one its a commercial $2200 AO Smith Cyclone, But there is a tankless of

93 EF !! A regular BW might be 60 EF or less
Reply to
ransley

Yes, I'd like to see a reference for how and why a tankless is supposed to be very inefficient in supplying water on demand to a dishwasher. That makes no sense to me. It fires up and instantly starts heating the water. All the heat goes into the water and into the dishwasher, except for the heat in the water left in the pipes at the end when the use stops. The latter happens exactly the same with a tank type unit. Nor do some of the other comments here make sense:

"1. We're concerned that it might not always give us as much hot water as we want. If washing machine and dishwasher are running, and someone is taking a shower, it could be stretched to its limit, and, if someone else turns on a hot water faucet, the shower might suddenly get cold bullets or whatever. "

You presently have a 25 gallon conventional unit and need a replacement that will fit in an 18" space, which would be more of a problem in that regard than a tankless. I don't see how anyone suddenly gets cold bullets with tankless. As more water is drawn, the outgoing temp of the water just drops following a smooth line.

"2. The supply of cold water to our house might not always be high enough pressure. We get the vague impression that our water pressure varies, possibly depending on usage by neighbors. It's probably not a problem, but it's one more minor worry. "

If you don't have sufficient pressure, then how are you going to deliver so much hot water to the washing machine, dishwasher, shower, etc that the tankless can't keep up in problem #1?

"3. We're thinking of putting in new insulated hot water pipes, running through our access-only attic, to all of our hot water faucets etc. A tank water heater would keep those pipes partly warm, so we wouldn't have to wait as long for hot water after turning a faucet on. "

Any type of hot water heater isn't going to do anything different with regard to keeping those pipes warm. Conventional hot water heaters have devices in them specifically to prevent hot water from rising out of them because it wastes energy. So they aren't going to keep those pipes warm either, unless you put in a circulating pump. I thought you wanted high efficiency? The only thing insulation will do is:

a - prevent some heat loss for the water on it's trip across the house

b - allow the water in the pipes to cool more slowly, so that if it's used again within an hour or so, it will still be warm.

Both those work exactly the same without regard to how the water gets heated

"5. If it turns out to have problems, the problems are most likely to be in our pipes or whatever, and not the fault of the manufacturer. Therefore, such problems would not be covered by the warranty. A lot of people regret getting a tankless for that very reason, and feel stuck with it, because it would cost them too much to replace it with a tank, having already spent their budget on the tankless. "

This I don't understand at all and sounds like FUD.

"6. When such problems happen, the plumber often can't figure them out, and spends too much time on them, then starting thinking of that customer as a problem customer. "

Certainly FUD. If a plumber can't figure out a tankless, you don't want that plumber around anyway.

"7. If energy prices keep going up, I want to consier other options, such as solar etc., and/or maybe get a geothermal heat pump for heating and air conditioning, and get hot water from that same system. If I spend a lot on a tankless now, that reduces my budget for that. "

If you go to geo, the difference in cost you would pay now of a tank vs tankless is going to be a tiny percentage in cost of that overall system.

Reply to
trader4

RIck-

Great post...no hype, no bashing.

Reply to
BobK207

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