kenmarks said:cnIsfg said:Tankless water heaters are OK for some one or two personal living situations but currently they are far from being viable system for larger families. In addition they waste a LOT of water unless you also have a reclamation system to capture unused water that is usually discarded as waste water while you are waiting for the tankless units to produce hot water.
Have you ever used a tankless water heater? You are sadly mistaken with both of these arguments.
1) With a tankless water heater you never run out of hot water. Very nice for larger families. I could run three showers all day long with mine.
2) There is NO wait for hot water. 185,000 BTU (Takagi) will instantly heat the water. That is why these water heaters are often called "instantaneous water heaters".

Yes I had the best tankless system you could buy a few years ago and it was still highly inefficient. There is nothing wrong with tankless systems as long as you unerstand the limitations especially the point at which they become more costly that traditional systems. For example your 185,000 BTU (Takagi will use more electricity in just 5 minutes than a traditional 80 GAL electric water heating system will use a entire 24 hour period and that is for an entire house! Just becuase tankless water heater provide instant hot water does not make it inheriently efficient. Exactly how do you think it gets water so hot so fast? Hint: a LOT of electricity!

cnIsfg said:kenmarks said:cnIsfg said:Tankless water heaters are OK for some one or two personal living situations but currently they are far from being viable system for larger families. In addition they waste a LOT of water unless you also have a reclamation system to capture unused water that is usually discarded as waste water while you are waiting for the tankless units to produce hot water.
Have you ever used a tankless water heater? You are sadly mistaken with both of these arguments.
1) With a tankless water heater you never run out of hot water. Very nice for larger families. I could run three showers all day long with mine.
2) There is NO wait for hot water. 185,000 BTU (Takagi) will instantly heat the water. That is why these water heaters are often called "instantaneous water heaters".

Yes I had the best tankless system you could buy a few years ago and it was still highly inefficient. There is nothing wrong with tankless systems as long as you unerstand the limitations especially the point at which they become more costly that traditional systems. For example your 185,000 BTU (Takagi will use more electricity in just 5 minutes than a traditional 80 GAL electric water heating system will use a entire 24 hour period and that is for an entire house! Just becuase tankless water heater provide instant hot water does not make it inheriently efficient. Exactly how do you think it gets water so hot so fast? Hint: a LOT of electricity!

I have the SETS system installed at home, it is electric, and altho isnt too great, havent noticed a jump in my electricity bill.
The main con I experience with this is that that the hot water is not even. We get bursts of scalding hot & ice cold water intermittently but finding a direct vent water heater was a pain and this had lifetime warranty...its good..but not for a shower and for more than 2 people in the house

Nostradamus said:cnIsfg said:kenmarks said:cnIsfg said:Tankless water heaters are OK for some one or two personal living situations but currently they are far from being viable system for larger families. In addition they waste a LOT of water unless you also have a reclamation system to capture unused water that is usually discarded as waste water while you are waiting for the tankless units to produce hot water.
Have you ever used a tankless water heater? You are sadly mistaken with both of these arguments.
1) With a tankless water heater you never run out of hot water. Very nice for larger families. I could run three showers all day long with mine.
2) There is NO wait for hot water. 185,000 BTU (Takagi) will instantly heat the water. That is why these water heaters are often called "instantaneous water heaters".

Yes I had the best tankless system you could buy a few years ago and it was still highly inefficient. There is nothing wrong with tankless systems as long as you unerstand the limitations especially the point at which they become more costly that traditional systems. For example your 185,000 BTU (Takagi will use more electricity in just 5 minutes than a traditional 80 GAL electric water heating system will use a entire 24 hour period and that is for an entire house! Just becuase tankless water heater provide instant hot water does not make it inheriently efficient. Exactly how do you think it gets water so hot so fast? Hint: a LOT of electricity!

I have the SETS system installed at home, it is electric, and altho isnt too great, havent noticed a jump in my electricity bill.
The main con I experience with this is that that the hot water is not even. We get bursts of scalding hot & ice cold water intermittently but finding a direct vent water heater was a pain and this had lifetime warranty...its good..but not for a shower and for more than 2 people in the house

Hello, hello? Tankless electric heaters are crap -- I totally agree. We are talking about GAS FIRED INSTANTANEOUS HEATERS. "My Takagi" used almost no electricy (just enough to fire a spark and run a small circuit board), NOT "more electricity in just 5 minutes than a traditional 80 GAL electric water heating system will use a entire 24 hour period and that is for an entire house." Sorry, but that is absolute bunk...

kenmarks said:cnIsfg said:I am not sure where you figures originate, but unless you ae buying off the back of a truck somwhere most modern gas tank water heaters have a BTU efficienty of at LEAST 80%. Most states mandate at least 60% efficiency to pass code.
Yes tankless water heater will save money in SOME light use situations. However using a tankless more than 15 minutes TOTAL per day will result in a higher net cost vs a traditional system with timers. That is NOT debatable. Plus when you now add the cost of mandatory water recovery systems the total cost of ownership skyrockets.
The efficiency figures you are quoting are for the efficiency of heating the water. I am not questioning those figures. Yes, they are mandated. The additional losses suffered by a traditional water heater, but not by a tankless water heater, are losses throught the top, bottom, and sides of the tank while the water is waiting to be used. These losses through the insulation are more difficult to quantify. They are not on the efficiency label. The insulation value is given, but it is not high enough to prevent any and all losses. If you had no losses, then your 80% or better would be actual. But these losses are actual and they are not accounted for on the efficiency label. Again, the efficiency labels for both tank and tankless heaters reflect the efficiency of heating the water only. No storage losses are included.
I speak from experience of having installed and owned 2 different tankless models and many tank models. Have you ever used a tankless heater???
From someone who is in the industry and design and test water heaters, the storage (or standby losses) are not enough for a normal household usage to account for much of the total energy bill. Again, the most efficient water heating technologies that exist today (not some fu fu dust) stuff are solar and heat-pump technologies. By the way, there is a DOE standard that tests water heaters (which take accounts for standby losses). Also, there is a 1-hr delivery tests which relates to the X gal label on the tank. For in-line water heaters of course, it is infinite.

george2001 said:

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Would something like this do the trick?

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This seems a nice addition to the existing hot water system.
But seems pricey at $300 +

This site gives you $50 off coupon for doing a simple survey (Code is valid for 1 month)

Has any one installed this type of instant hot water system in their home? Any reviews?

Thanks..

Just so happens that I recently finished a home built version of the d'mand system that can be duplicated for about $100 depending on eBay auction prices.

We have a 30-35 ft run of 7/8" copper from the hwh to the sink in the mbr. I added my home built version of the d'mand system under the sink - I put a push button under the sink - when pushed, it takes 2 minutes for the pump to circulate hot water to the faucet (and also to the shower) after which, the pump shuts off. We like the fact that we're not wasting water and power. The Taco pump hums just enough for you to know that it's still circulating.

I went onto eBay and searched for "Taco Pump" - there is a seller who offers the pump from the d'mand system - typically for under $70 plus shipping - his site includes a link to the instructions for installation.

We really like the system.

1thomas said:I did quite a bit of research and came to the conclusion that it would take around 11-22 years for me to recoup the extra cost of the expensive install / upgrade of a tankless water heater.
Your analysis is quite sensible. While a tankless heater would save energy and money, if the payback is that long it really probably is not worth doing.
In my position I was eliminating two older electric heaters with one tankless heater as well as switching a 3685 sq ft home with up to 21' vaulted ceilings to gas heat from electric. I had the time and ability to do all of the work myself and my payoff was very quick (for good or bad I no longer have that much time now...).
I did incorrectly state the specs of the Tekagi and want to correct it so as not to be misunderstood. I said the power input is 185,000 BTU. Actually it is 20,000 to 185,000 BTU. There is a flow meter and the heater uses just as much gas as is necessary to raise the water to the set temperature. If the flow is low like one faucet, it will only use a smller amount of gas. If the demand is large (like 3 showers running at once), it will crank up the gas flow.
The thermal efficiency is 85% and there are no losses from storing the water (which is not minimal as "someone who is in the industry" stated).
Here is a good question. Why do Americans use tank-type heaters and many other countries use tankless? Do you think it might be because status quo is the norm here and saving energy (which is more costly elsewhere) is more important in other countries? Kind of like 14 mpg SUVs versus 60 mpg Polos...

How much longer does it take hot water to get to the point of use with a tankless heater compared to a tank unit? Does anyone know? Thanks in advance....

1thomas said:I did quite a bit of research and came to the conclusion that it would take around 11-22 years for me to recoup the extra cost of the expensive install / upgrade of a tankless water heater. I'm sure this is over-simplified, but here's my data in a nutshell.
Cost of professional install of a 40gal 12yr tank water heater at home depot: $700 ($400 if you install yourself and don't need extra pipe/parts).
Cost of pro install / upgrade of piping of comparable tankless: $2500-3500. Avg quote was $3000.
In Austin TX, there are currently $600 worth of rebates, so lets just say minimum cost of tankless was $2000.
2000-700=$1300 more for the tankless, assuming you can get all the rebates....and that's probably a minimum extra cost.


The only gas appliance in my house besides the furnace, is the water heager (2 bathroom, 2-3 people living there). My summertime gas bill (no furnace in use) averaged about $20, of which about $10 was the line fee and taxes. .... So, I'm only spending about $10/month in the summer for a 40 gal water heater.
I realize that in the winter due to cold pipes, this efficiency will go down, but I don't think having a tankless would be THAT much more efficient, besides whatever cooling effect the copper pipes have on the water sitting in the tank (while it's in the tank). Since the tank is in the house, which is also heated to the same approximate temp as it is in the summer, I doubt it costs that much more over the winter to keep the water warm in the tank.
Bottom line is that I seem to pay $10-12/ month for the water heater tank (since the line fee/taxes are there anyway.
How much of this per month could I possibly save? Even if I save the whole $10/month, we're talking 11 years before I see any savings. The more likely reality is that I'd only save $5/month, so then we're talking 22 years before saving anything.

Besides the consideration that the 12yr tanked water heater will probably wear out in around 15yr, and the tankless might last longer, I think the proposed savings is just a bunch of hype. You'd do much better to invest the saved money now.

If you install it yourself, it might be worth it, otherwise, my guess as to why there's so much hype on them now is because the installers make so much more on each one.

"saving money" by installing a tankless water heater seems like a big scam to me.
If you really want to save, make sure you use a gas heater instead of an electric. That's where the big savings are, as electrics seem to cost nearly twice as much as gas to run.

When reading reviews of customer savings, note that many of them convert from electric tank water heaters to gas tankless, and are happy, not realizing that the real reason they're saving major $ is due to the gas vs. electric equation, not tank vs. tankless.

I'm not a pro, or a plumber. Just a fatwalleter that had a dead water heater and checked out the options, and installed a 40gal tank myself yesterday. Wasn't that hard.

I totally agree. I thought a tankless heater would save me money and be more fuel efficient. I had a formal energy efficiency audit done (infrared camera, blower door, the whole bit...) and learned that it would take 20 yrs for me to pay off the initial investment in an instant hot water heater because I heat with oil. The more affordable instant heaters are gas/propane. Oil tankless heaters are >$1500. No option for natural gas in this state so until I decide to add propane as a 2nd fuel source its definitely not worth going tankless.

1st i've heard of a tankless water heater...

Funny noone out of all these post mention that if you actually CLICK the site and read it says you have to have a licensed contractor do the install for another $400 and you have to send in thier federal ID # on the receipt.