Page 1 of 4 1234 LastLast
Results 1 to 10 of 33

Thread: On-demand hot water heaters

  1. #1
    Join Date
    May 2007
    Location
    Kansas City, Missouri
    Posts
    13,431

    On-demand hot water heaters

    My hot water heater has been going out about every other day. I've replaced the thermocouple with two different brands and is still happening. I think I've determined that the gas valve is going bad. It's about 6 years old and not sure that it's worth replacing just the gas valve ($150 new/discontinued) as it's not great quality.

    It also sits right in front of our Washer, so to gain some real estate in the laundry room, we've been considering the tank-less on-demand models.

    I'm just not sure how many gallons per minute I should consider. We've got 2 full baths and may run the washer (high efficiency) and dishwasher about the same time of day as taking showers, but rarely both at the same time.

    So does anyone have a tank-less natural gas unit, if so, what brand? how many gpm? what is you're review of it?

    Thanks
    Darren

    To a small child, the perfect granddad is unafraid of big dogs and fierce storms but absolutely terrified of the word “boo.” – Robert Brault

  2. #2
    Join Date
    Jul 2011
    Location
    The Gorge Area, Oregon
    Posts
    4,698
    Don't but a few things we found when looking and talking to friends about them:

    They take a fairly good sized gas line. Ours wasn't big enough to drop in, I think a 3/4" line was the smallest we could find (this was 3? years ago or thereabouts). That's mainly why I don't have one today because the gas feed line to that side of the house was only 1/2"

    A friend got one and "up sized" it a little to much. Apparently it had a flow rate threshold for kicking on and their low flow shower wasn't sufficient to make it turn on. So when you took a shower at his house you'd have to crack the hot water on in the sink or you'd never get a hot shower. I think some of the newer ones are smarter than this (and he also bought one that was basically "hotel" sized which was wayyy to big).

  3. #3
    Join Date
    Feb 2008
    Location
    East Freeetown, Massachusetts
    Posts
    3,016
    I have only 3 choices to heat hot water

    1) Propane --- NO - not the way to go
    2) Electricity - I did think about it
    3) Oil - that is what heated the water here for years - and that is what I choose.

    I had in the furnace tankless hot water. That developed into a host of problems.

    What I chose to do was to install what is called an indirect hot water tank. In my situation, it just came out as my best option. It is a separate hot water storage tank that gets it's source of heat from the furnace via a separate "zone". The aquastat draws heat from the furnace as needed to maintain the water in the storage tank. Coupled with a high efficiency furnace it is competitive with just about any other source of hot water. I do NOT have a high efficiency furnace - YET.

    I did the install of the indirect hot water heater, including adding a 3-rd zone the the existing furnace. I also added in some whole house filters. All together it took 1-1/2 days for the installation. I was alone with no help.

    Indirect hot water can be coupled with any furnace that makes hot water - as in baseboard hot water heat.

    I did give thought to the on demand hot water, but that would have had to be Propane. I don't know if you know this - but Propane is normally very expensive - except for this year - it is 3x more expensive than normally expensive. Not a good source of heat.

    I LOVE - the indirect hot water. I will recommend it as a valid choice for hot water.

    My oil consumption has been reduced by 50-60%

  4. #4
    Join Date
    Aug 2008
    Location
    Reno, Nv
    Posts
    3,632
    We have had the Rockstar treatment with water heaters...except for the last house . For the last 15 years we've had tankless from Rinnai (http://www.rinnai.us/tankless-water-heater/). Tell it when to go on and when to go off..."Fast Start" button if you get sprayed by a skunk!! Metered water being what it is in the US now...hard to beat. We have always had the gas fired model...they are great! More, not much...but more standard maintenance, but nothing a beer wont fix
    Your Respiratory Therapist wears Combat boots

  5. #5
    Join Date
    Oct 2006
    Location
    Tokyo Japan
    Posts
    15,807
    Yep the Rinnai units rock, that is just about all we have here in Tokyo, they really do work well, I would not want anything else.

    When we had two daughters in the house I could still get a nice hot shower after they both had their showers. Our main unit in the house has a nice feature, you can crank the temp up to 60C/140F if you want, this is great for cleaning some things, you can get HOT water! Usually we keep it at 43C/109F. Our unit is not really comparable to what you would get in the US, it runs the kitchen, and the bathtub room too, and it can fill the tub with hot water at the touch of one button, and it can reheat water from the tub too, I doubt you can buy that in the US.

    Love these units, way cheaper to us natural gas here than electricity too.

    Cheers!
    The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
    William Arthur Ward

  6. #6
    Join Date
    Aug 2007
    Location
    Buse Township MN
    Posts
    565
    We just went thru this thought process and settled on a hybrid hot water heater. It is installed in our walkout basement. Our pellet stove is there as well so plenty of heat in the winter for the heat pump to do it's thing. There are 4 of us, 2 adults, a teenager, and our soon to be adopted 7 year old. Works great so far. Reviews are all over the map online but we thought it was worth a gamble.

    http://products.geappliances.com/App...ku=GEH50DEEDSR
    Every child deserves a family. Adopt. Foster. Get involved.

  7. #7
    Join Date
    Nov 2006
    Location
    Mountain Home, Arkansas
    Posts
    11,825
    Consider checking with your electric company. Some have lease or sale plans for high efficiency water heaters. As for the on-demand types. I have heard good and bad reports from those who have them. My son has one and it takes forever for hot water to get to the faucet. A friend has one and loves it. Before I would get one I would do a lot of homework.
    "Folks is funny critters."

    Think for yourselves and let others enjoy the privilege to do so, too. ~Voltaire

  8. #8
    Join Date
    Dec 2012
    Location
    Bedford, NH
    Posts
    1,683
    Quote Originally Posted by Leo Voisine View Post
    ..............................................
    What I chose to do was to install what is called an indirect hot water tank. In my situation, it just came out as my best option. It is a separate hot water storage tank that gets it's source of heat from the furnace via a separate "zone". The aquastat draws heat from the furnace as needed to maintain the water in the storage tank. Coupled with a high efficiency furnace it is competitive with just about any other source of hot water. .........................

    I LOVE - the indirect hot water. I will recommend it as a valid choice for hot water.
    I have the same system as Leo. Very responsive, simple design, works very well & is cost efficient.

    Like any other system, when turning on the hot water faucet all the cold water in the line must exit before the hot water arrives. I think that in itself is an opportunity for a great invention to save all that wasted cold water. Have given thought to the cold water being redirected for recycling purposes (until the hot water arrives), but haven't come up with a viable solution.
    Thoughts entering one's mind need not exit one's mouth!
    As I age my memory fades .... and that's a load off my mind!

    "We Live In The Land Of The Free, Only Because Of The Brave"
    “The problems we face today are there because the people who work for a living are outnumbered by those who vote for a living."
    "
    Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill

  9. #9
    Join Date
    Mar 2008
    Location
    new york city burbs
    Posts
    10,184
    I have a tankless unit. for us, it was a necessity.
    My house is a tiny cape. The hoter water heater and tank was behind my fridge, so accessing it whenever was a disaster, and ruined many kitchen floors
    Once we converted, its just a box on the wall, and it works great, all the hot water you want.
    We still have to turn down the heat first when its in the teens to get quick demand to our shower(we have 3 heating zones, and although domestic water is supposed to come first, seems it lags for a bit, and we want it instantly)
    Its a lot better than the previous heating system we had here.
    I couldn't tell you a thing about it, as Im not familiar with that kind of stuff.
    works great, we can run a washing machine and take showers continuously, even 2 showers at a time.
    Human Test Dummy

  10. #10
    Join Date
    Aug 2007
    Location
    Reno NV
    Posts
    13,356
    Quote Originally Posted by Al Launier View Post
    Like any other system, when turning on the hot water faucet all the cold water in the line must exit before the hot water arrives. I think that in itself is an opportunity for a great invention to save all that wasted cold water. Have given thought to the cold water being redirected for recycling purposes (until the hot water arrives), but haven't come up with a viable solution.
    They have these systems that recirculate the hot water that is supposed to address the issue.

    Don't know much about them other than having seen them on some of the home improvement shows. Supposedly, they can work with existing plumbing, but I'd think a dedicated return line would probably be better.

    Click image for larger version. 

Name:	Hot_Water_Recirculation_Process.gif 
Views:	127 
Size:	90.1 KB 
ID:	81498


    Programmer - An organism that turns coffee into software.
    If all your friends are exactly like you, What an un-interesting life it must be.
    "A door is what a dog is perpetually on the wrong side of" Ogden Nash


Similar Threads

  1. Water Heaters - Gas or Electric?
    By Carol Reed in forum Off Topic Discussion
    Replies: 17
    Last Post: 06-02-2015, 07:56 PM
  2. Any demand for White Pine
    By larry merlau in forum General Woodworking Q&A
    Replies: 6
    Last Post: 03-12-2013, 09:54 PM
  3. Heaters ......
    By Rob Keeble in forum Off Topic Discussion
    Replies: 24
    Last Post: 02-02-2013, 09:16 PM
  4. How do people demand so much for the work?
    By John Daugherty in forum Off Topic Discussion
    Replies: 26
    Last Post: 11-18-2011, 05:50 PM
  5. By Popular Demand
    By Jeff Horton in forum Old Iron
    Replies: 11
    Last Post: 08-07-2007, 11:47 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •