Tankless hot water heater advice < MeM > 05/14 01:41:56
wanted. My 25 year old 40 gallon tank just gave up the ghost, and I’m considering my options. I would prefer to install a new heater, of whatever type, myself. Options: install a conventional 50 gallon tank, or install a tankless system.
The house is in the S.F. bay area, 4 bedrooms, 2 1/2 bathrooms, dishwasher, clothes washer. Only 2 occupants at this point. We probably won’t be living here more than another 5 years.
Questions: (1) are the energy savings over only 5 years worth the extra expense of a tankless system? (2) What brands have proved the best? I’ve heard Takagi. How reliable (i.e., trouble-free) are tankless systems really? (3) I have yet to find any installation instructions and diagrams for tankless on the internet. All I know at this point is 3/4″ gas piping, 3/4″ copper, 120 volts/low amperage to run computer gadget, 4″ stainless flue (my current one is 3″). Anyone got a web site for me? (4) Apparently there are some new code rules for conventional tank installation, but I can’t find those by looking through the UBC for California, and there is zero, zip, nada about tankless in the 2001 UBC. Anybody know what these are, other than the obvious like strapping? (5) Is there a book about installation of tankless? I don’t recall seeing any articles in Fine Homebuilding on tankless.
etc., etc. All opinions welcomed.
Replies
If you go to "google" and type in" tankless water heaters" you can get lots of information. I looked into this and I don't think its for me.
The 5th item on their list " controlledenergy.com "has a good rundown on how they work
Edited 5/14/2004 9:54 am ET by ARROWSHOOTER
Edited 5/14/2004 9:54 am ET by ARROWSHOOTER
lots of discussion on this site recently, do a "search" and read up.
tankless pro/con:
- smaller size (takes up less space in basement)
- there is an upper limit to how much water flow can be heated, beyond a certain point. Depending on your incoming cold water temp, and your shower head flow rate you can find yourself unable to take a hot enough shower, in worst case.
- some posters mentioned trouble getting a small flow of hot water (like, just to wash your hands) because the machine does not kick on until a certain flow rate is reached.
To overcome some of these, some have proposed to put a tank type water heater upstream of the tankless (to raise the temp to a minimum point for maximum available hot water flow).
The cheapest, and most flexible set-up is two tank type water heaters in series. But this takes up twice the room of your existing unit, and is not as 'sexy' as a tankless set up.
A tankless might not last any longer than a tank type, depending on your water chemistry, and costs many times more than a tank type to replace.
Hope this helps, do the "search" and good luck,
Norm
> The cheapest, and most flexible set-up is two tank type water heaters in series.
How about a hybrid approach: Replace the second tank with a tankless. The first tank could just provide a steady 80 - 90 Fahrenheit source to the tankless. Running it at that low temp. would mean a low temperature difference across its insulation, so it should be quite cheap to run and last a long time. The following tankless gets water with a real good head start on getting up to the temp you want, and it's buffered from city supply temperature variations. You can always get enough for a hot shower. For the hand washing trickle situation, if the tank temperature without any cold mixed in at the faucet is comfortable, then you can just use it that way without the tankless kicking in.
-- J.S.
The only real reason for using a tankless is to save space. It doesn't reliably provide any more capacity than a standard tank, nor does it reliably provide lower operating cost.
check out parts prices and availability too. tank type do not have many parts, and they are avail.
Tankless hot water heater advice < MeM > 05/14 01:41:56
wanted. My 25 year old 40 gallon tank just gave up the ghost, and I'm considering my options. I would prefer to install a new heater, of whatever type, myself. Options: install a conventional 50 gallon tank, or install a tankless system.
The house is in the S.F. bay area, 4 bedrooms, 2 1/2 bathrooms, dishwasher, clothes washer. Only 2 occupants at this point. We probably won't be living here more than another 5 years.
Questions: (1) are the energy savings over only 5 years worth the extra expense of a tankless system?
A. Kinda of hard to tell, our experience is that it varies from the water chemistry to the climate and how much you use it.
(2) What brands have proved the best? I've heard Takagi. How reliable (i.e., trouble-free) are tankless systems really?
A few years ago I would say that they were problematic, but Takagi, a long time Japanese maker of tankless, got it right. Very easy installation. ( They also makethe AquaStar brands)
(3) I have yet to find any installation instructions and diagrams for tankless on the internet. All I know at this point is 3/4" gas piping, 3/4" copper, 120 volts/low amperage to run computer gadget, 4" stainless flue (my current one is 3"). Anyone got a web site for me?
A: Check the websites. The AquaStar does come with a video explaining the entire install procedures both for indoors and outdoors.
(4) Apparently there are some new code rules for conventional tank installation, but I can't find those by looking through the UBC for California, and there is zero, zip, nada about tankless in the 2001 UBC. Anybody know what these are, other than the obvious like strapping?
A: Ask City Hall, with so much changing they sometimes don't have time to update websites. Just pick-up the phone
(5) Is there a book about installation of tankless? I don't recall seeing any articles in Fine Homebuilding on tankless.
A:Call or write to the Tankless makers, I've found them pretty responsive and willing.
etc., etc. All opinions welcomed.
Lastly wife and I lived overseas where everthing was tankless. Upon returning, we moved back to the states (Southern Cal) and immediately changed out our old tank for an AquaStar (made by Takagi). Everything is pretty straight forward, we did it in an afternoon. I've met many local contractors warming up to them as well. The only drawback I see with your scenario is the price ratio to your time frame. You may just break even.