Changing to 1/2 pipes

Discussion in 'Tankless Water Heater Forum' started by ChuckS, Mar 27, 2009.

  1. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    As I keep saying, the problem with our new tankless is the time it takes to get hot water. All of the pipes except the last little bit that goes to the facets are 3/4". I am wondering, what will happen if I change everything on the output side of the tankless to 1/2" pipes? What negative effect would that have?

    My logic is there would be less water to clear out the pipes before we get to the hot stuff...
  2. Terry

    Terry Administrator Staff Member

    Messages:
    14,911
    Location:
    Bothell, Washington
    It will no longer meet plumbing code for one.

    You will be reduced to using only one faucet at a time.
    Everyone in the house will have to take turns using water.
  3. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    Bad idea I guess, I don't want to be against code...
  4. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    You should ask Greggy. It's probably all your imagination or something you did wrong. :D
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,516
    Location:
    Cave Creek, Arizona
    pipes

    If the tankless replaced a tank type, the time it takes the water to get there should be EXACTLY the same as it was before. Tankless give you more hot water, not faster hot water unless you move the heater closer to the bathroom.
  6. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    The tankless was installed about 20' further from where the old tank was. So he ran a 3/4" X 20' line and tied it in where the old tank heater was. So now we have 3/4" X 20' delay on top of the delay from the old tank heater.

    Our kitchen facet flows at exactly 1gpm according to my scientific testing. I timed how long it took to fill an empty 1 gal milk jug and it was exactly 60 seconds.

    I added a recirculation loop which cut the time to hot water from just over a minute down to about 45 seconds. Unfortunately there seems to be a bottleneck in the recirculating loop where the water goes into the input side of the tankless heater. The bottleneck appears to be twofold, 1. the recirculated water has to compete with the city water pressure for a place to go and 2. the tankless heater limits how much water it allows in by it's ability to put up to temp water out.

    What I really need is a tank or bladder that can quickly take the 2 gals of cold water that is sitting in the 35' of 3/4" lines then slowly release it into the input side of the tankless as we use hot water so te tank or bladder will be empty and ready for the next water use.

    Something similar to the lungs in our body that can suck in 2 gals in say 20 secs on the inhale phase then after about 30 seconds of holding the water, exhale slowly but with enough pressure to win the contest against the city water so it can be emptied by feeding the water back through the water heater so the tank is emptied and ready for the next cycle.

    My imagination takes me to an in line expansion tank with a compressor. If the air pressure would quickly drop when you turn on the facet it will allow the 2 gals of water sitting in the lines to enter the expansion tank. Then the compressor can kick on say 1 minute later. As the compressor increases the air pressure in the expansion tank, th expansion tank will begin releasing its content back into the system... I have no idea how to build something like this or what kind of parts to use but this would work great according to my feeble mind...
  7. Mad Plumber

    Mad Plumber Mad Skills

    Messages:
    222
    [​IMG]
    Well gosh. Now we have monkeys so smart that they are doing pluming stuff.
    And now you go ands ask that qestion, and it makes me feel kinda lik a monkeys uncle. I cant figger it out either.
    What do you mean breathe in and out.
    You mean like a scuba diver?
    Do they are breathing water in and out, and it gets warmer?
    So the water get waremer. then then you drink it.,
    But is it good to drink water that has been in a scuba divers lungs?
    Does this seem right?
  8. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Puttin a re-circ line on a tankless usually voids the warranty.
  9. Ladiesman271

    Ladiesman271 Homeowner

    Messages:
    221

    Not if you follow the directions that are supplied with a lot of tankless heaters. Then again, you have to read the directions first before you can follow them!:eek:
  10. Ladiesman271

    Ladiesman271 Homeowner

    Messages:
    221



    Do you have a water shortage? If not, why are you spending your time and money on a recirculation system?

    I doubt if your recirculation system is installed the correct way. If the recirculation system was installed the correct way, hot water would be at the tap in a few seconds after you turn on the tap!:confused:
  11. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    One more stooge and you guys would have a career in movies.
  12. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    See diagram... http://img153.imageshack.us/img153/7736/recirculationfv9.jpg

    Mine is not a normal recirculation system that runs on a timer etc...

    I have a flow switch that kicks on the pump as soon as a facet is opened. The aquastat then turns the pump off when the line gets hot. This way the recirculating system only runs when I need hot water instead of paying to heat water when not in use.

    I can also turn a facet on and then off again when I go to the rest room to start the recirculating system and by the time I am done doing my business, I have hot water ready to go.
  13. Redwood

    Redwood Master Plumber

    Messages:
    7,452
    Location:
    Connecticut
    Redwood points the spray in laddy boys face and....
    PPPFFFFSSSSSSSTTTTT

    [​IMG]
  14. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    This is from my heaters warranty. From my guestimation, I still have the full warranty with the type of loop I installed but would still have 3 years warranty even if my loop doesn't qualify.

  15. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    and what is the warranty without the loop at all? 3 years goes by real fast.
  16. fine tuneing a tankless system....be careful

    [​IMG] when you are all done trying to make it work as good as the tank type heater you will probably have something like this....

    so be careful not to pipe yourself into a corner.......
  17. ChuckS

    ChuckS New Member

    Messages:
    96
    Location:
    Aurora, CO
    No chance, I used pex which eliminated all those 90 degree elbows. It is also easier to squeeze out from between the pipes...

    [​IMG]

    @nhmaster = 10 years.


  18. Hell I got that problem right now,

    and I'm thinking of getting a "tramp stamp" right there at the crack that states:


    "10% off your bill if you happen to see this unsightly cleavage." :eek:

  19. Yes

    LOL!
  20. thinking about getting my crack waxed....

    RUGGED, Just like in that picture, I have been having troubles
    lately that way myself, looking like a gorilla with hair growing everywhere
    but on my bald head...

    I thought of getting it waxed,


    but in this video it looks way too painful for me,

    http://www.ebaumsworld.com/video/watch/80574410/


    maybe any new apprentices should have this done






    [​IMG]




    [​IMG]
    Last edited: Mar 30, 2009

Share This Page