Tankless water heaters?

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First time poster here, and not too smart when it comes to water heaters. Looks like I might be needing a new one (natural gas), so I've been looking around. What's the deal with these tankless units? Sounds like a great idea to me, but are there any downsides? Can I install it myself? I'm pretty much a do-it-yourselfer; I know how to solder copper pipe, and I can handle simple wiring jobs, but I've never messed with gas pipes and fittings before. Any words of wisdom you have (pertaining to water heaters, that is) would be appreciated. Thanks.
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You probably can do the replacement yourself. It's not rocket science. The biggest issue is the gas connection. If it is made with black iron pipe and the new water heater has its gas connection in the same place as the old one you're all set. Use a good pipe dope like RectorSeal. If not you may need to cut and thread pipe. If the gas connection is flexible your job is easier.
Copper pipe connection is no challenge.
Make sure the (flue) vent is reconnected properly too.
Just make sure to check for gas leaks. A viscous soap and water solution and a small brush is what I use.
RB
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I would research very carefully to see if they are really efficient and not just the latest gimmick. They were used decades ago and dumped because they didn't work. Not enuf hot water and expensive to run.

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They've been using them in Europe for 30 or 40 years. Maybe 50. More energy efficient, quite effective . . . bugs worked out long time ago. The only downside that I remember is a bit of a roar while you're using hot water.
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On Mon, 07 Jun 2004 23:38:59 -0400, Sporkman

Another down side is that the flowrate is lower. This might be resolved by now, but I remember getting cold water in the shower when someone else would use hot water in the house that was on the same waterheater. This was about 10 years ago.

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Flow rate depends on model, Just size it right. and be sure your gas line and supply can handle it . 188000 Btu Takagi takes alot of gas, my 117000 btu Bosch handles a shower and sink fine and Ive never needed it set to max. New units are very flexible in output , one even has a remote thermostat,a nice option. For 2 showers or a family the bigger 188000 btu should be used.
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i dont know what code or the regulations are in your area, but in my town you cannot tie into your gas line yourself. it has to be done by someone certified, and then inspected by the gas company.
maybe in your area you can do it yourself. at any rate you can easily do the rest of the work and the gas line isnt hard either, but it has to be done right...
as for the on demand systems (tankless), as someone else mentioned they can get loud from the burner blazing away. so it depends on where the tank is located in relation to areas you want quiet. they may have newer quieter ones than i know of too. im sold on them. next time it comes up thats the way im going. it will be in the basement though so noise wont matter...
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The local Habitat for Humanity has been installing them in new three bedroom houses for almost two years without problem.
TB
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Steve Turner wrote:

Good ones available today are fine. However they only save standby heat. If you use a lot of hot water all day, little or no savings will be seen.
They also have a problem with high/low volume. The better units have multi output levels and handle it fairly well, but for most of us the old tank style is the best bet. If you have a weekend home, I would not consider anything else.
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On Tue, 08 Jun 2004 02:50:23 GMT, Steve Turner

The tankless are good if you have very limited space, such as in a trailer. They cost a lot more than the tank units.
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We installed one in our house here in Austin TX about four years ago, replacing an aging 40 gallon gas heated tank. The installation was pretty easy if your really handy..The most difficult thing was replacing the flue stack..Most old tank heaters use 3" flue, and the tankless use either 4" or 5"..We installed a Takagi TK-1, which has a power vent so it required the 4" so we had to remove the old one, cut the hole in the roof bigger and install it..The installation benefit was two major things. First, no end to hot water..With three adults showering in the morning, person number three usually had luke warm water at best..With the tankless, everyone was happy...The Takagi can keep up with two showers easily... Second was the savings..As someone mentioned if someone is there all day long using hot water you may not see a savings or even might see an increase, but nobody is home all day in our house..Our gas bill went down conciderably..
As for sound, ours is inside the house, in a closet in the laundry room..IF you in the same room you here a faint "whoof" as it lights, and that is all..It's not loud at all..We even opted for the optional remote thermostat control which is really nice..To take showers we set it on 102 degrees and shower only with hot water...No mixing needed...To run the dishwasher or laundry you can run it up as high as 167....Really cool...We have not regretted one day we installed it..I do feel though had we installed the cheaper Bosch units they sell at Home Depot we may not have been so happy...I understand they don't supply enough hot water to run two showers...The Takagi was about 900.00 delivered to the door...Our reasoning was less for savings and more for the demand of hot water... Hope this helps! John
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John wrote:

Hey John, I'm here in Austin too (Pflugerville, actually).

Great information, thanks. After lots of looking, I'm currently leaning towards the Takagi T-K2 (or the T-KD20; anybody know the difference?). Sounds like it would do everything I'd ask of it.

Not too worried about the sound; it'll be out in the garage. I have an air compressor out there that kicks on from time to time and nobody seems to mind (even at 2:00AM!).

Hmm, interesting. Trying to decide if I'd really use that or not. Probably would if I had it! :-)

Yeah, two simultaneous showers is the test; I'll have that a lot. Wonder what happens when you have the dishwasher going too? =:()

Yes it does. Thanks!
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You dont want the unit to freeze in the garage.
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Good point, but I don't think that'll happen here in Austin. Most of the houses around here have water pipes in the garage.
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On Tue, 08 Jun 2004 19:04:06 GMT, Steve Turner

In fact, in AZ, I think having the water heater in the garage is a good idea, as the garage will be hotter than the water in the heater at times!
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The Takagi has built in freeze protection that will cover Austin winters easy..So no problem there.. John
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Dang, I forgot to ask: When comparing the two types of water heaters, do the tankless units introduce any noticeable delay in supplying water to the faucets at the desired temperature? Not that it's a big issue because I think my house must have 98 miles of pipe between the current water heater and any given faucet, but I'm just trying to understand all the variables. :-)
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Hi Steve.. The delay between faucet on and "whoof" is about one second..I don't find it any longer with the tankless model..Our old house too has a million feet of pipes I think..(all that wasted water bugs me) Hope this helps! John

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My Bosch is quiet, handles flow well - 28000- 117000 btu. If you run 2 showers get a Takagi, 188000 btu . Bosches bigger unit is made by takagi. My unit has battery ignition , 2 D cells, mine are 2.5 yrs old. You need gas flow , i needed 3/4 for the 117000 btu. They do save money I save at least 50%, and have 7$ gas bills in summer now and I cook food alot. A worthwile investment. Plus they last 30 yrs, no tank to rot out. they even have one with a mini hydro generator for ignition. They are 82-83% efficient.
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Wow, good info guys; thanks (although it looks like some of you don't sleep at night!)
Now for my next set of questions. :-)
After I posted last night I did a little more research, and now I'm wondering what would be wrong with switching over to an electric unit instead of gas...? Looks like they are smaller and much easier to install (though I didn't delve deep enough to find out what the initial unit costs are). However, I'm wondering if they can keep up with the gas units in terms of volume? I have a wife and three young girls in the house, so I don't think I need to tell you what that can mean for a water heater! :-)
Also, any info on what brands you feel are the best is appreciated. I assumed the models made by Bosch (do they not make electric units?) would be a good choice, but at least one poster had some reservations about them.
Thanks again.
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