Faster/more efficient hot water

Discussion in 'Water Heater Forum, Tanks' started by DIY, Feb 9, 2010.

  1. DIY

    DIY New Member

    Messages:
    153
    Location:
    Florida
    Hi all,
    Right now with my present setup to my hot water heater is @ 22 to 25 ft. of 3/4" pipe. Was wondering If I changed nearly 5' of that 3/4" pipe to 1/2" pipe that is inside of my house that is directly routed up to water heater.Would that speed up the hot water delivery to the kitchen,bathroom faucets and tub/shower? As of now it takes a good 30 seconds before any sign of hot water comes from any one of these faucets when the hot side is turned on.

    Thanks to all who reply!
  2. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,328
    Location:
    Yakima WA
    It would obviously help some, but not much. Changing all of the 3/4 to 1/2 would help a lot, but it would cut down on flow. The best think in my opinion is a recirculating system. This would give you virtually instant hot water.
  3. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    As Gary stated a recirculating system would give you better results (put it on a timer to only recirc the water at the times when you need it). To answer your question, yes - downsizing to 1/2" would speed up the water but doing it for 5' would be almost undetectable and if you ran multiple fixtures you would find the volume of the water would be lacking.
  4. DIY

    DIY New Member

    Messages:
    153
    Location:
    Florida
    Thanks for the replys Gary & Florida Orange

    I have no room for a recirc. system. The water heater is located in the kitchen. Under counter top low boy type. There is 1 -1/4" between HWH and
    a 30" stove,on the other side of HWH, there is 3" " between HWH and a stacked washer/dryer,and to make things really fun there is 1" between the bottom of the counter top and the top of the HWH. It is looking more and more like replacing all 22 to 25' of the 3/4" pipe to 1/2" pipe...My big thing is If I do all that (i mean not real big footage to dig up) would it be noticeable at the faucet right away,and my water bill?

    Thanks all
  5. nukeman

    nukeman Nuclear Engineer

    Messages:
    709
    Location:
    VA
    Normally, you have the main lines at 3/4" and branch off the 3/4" into 1/2" to feed individual fixtures. If you are talking about putting everything in 1/2", it will not be big enough to feed everything.

    Even if you put everything in 1/2", your delay in getting hot water will be cut in half (say 15s delay instead of 30s). I don't see this as cost effective. Probably the best bang for your buck will be to insulate all of the hot water piping that you have access to. You will still have a long delay if the water sits for along periods without being used (say overnight), but would really help out during the day when there is less time between draws.

    You other option may be to add a small WH under the counter on the fixtures where you have the most delay (say one under the kitchen sink and one under the bath vanity). I am not sure why you have the delay at the kitchen sink when you say the WH is also in the kitchen. Maybe something else is going on here. Do any fixtures get hot quickly?
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,486
    Location:
    Cave Creek, Arizona
    You would have to run about half as much water to empty the cool water out of the pipe, but you would have more pipe surface, compared to the volume of water in the pipe, to heat up as the water flows through it. You would also only have half as much volume available at the faucet, but that might not be too noticeable if your faucet does not need, nor can it use, the full volume. That short of a distance would not be a good candidate for a circulation pump anyway.
  7. FloridaOrange

    FloridaOrange Plumbing Designer

    Messages:
    1,317
    Location:
    SW Florida
    You could install one of the point of use recirc systems at the furthest sink. It would require a receptacle and space under the counter of the bath (if that's the furthest fixture) for the pump and a timer.
  8. DIY

    DIY New Member

    Messages:
    153
    Location:
    Florida
    Thanks for the replys all, appreciated!
    This is getting crazy...Next door About 7 + years ago It was re piped. At the time the plumber allowed me to do the grunt digging and so forth. 3/4" pipe was used for the main and it ran all the way up to the house.From the outside of the house 1/2" piipe was then used to go into the house and feed all the fixtures. Next door where I am we ran almost the identical pipe route up to house and fixtures (actually in some spots while digging we saw parts of the main for next door) The only thing different is the hot water heater at my place was moved over 3' and the 5'of hot water line in the house going to the HWH is 3/4" pipe instead of 1/2". This might be out there..,but would the capacity of the HWH in any way remedy this. If so... the biggest capacity in a low boy type i can step up to is 40 gallons.
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,892
    Location:
    New England
    I have a RedyTemp recirculator in my upstairs bathroom (vanity cabinet). It's probably the easiest (plumbing) install of any available units and should literally only take maybe 10-minutes. But, you need a place to plug it in. It often isn't too hard to drop a lead from the box near the vanity down and put a new receptacle in the vanity. I have mine on a 7-day timer so it only runs when I'm normally home. In the winter, it runs maybe 5x per hour for about 40-seconds. I have it adjusted to provide only warm water, but you can easily select hotter by just turning the aquastat knob on the front panel. If you don't have a dedicated return line, it pumps the water from the hot side into the cold side. This is true for any install that doesn't have a dedicated return line. By setting it to only provide warm, flushing the toilet purges all of that (for me, anyway), and then I have both hot and cold at the vanity. My tub/shower is closer to the WH, so has hot when the vanity has warm.
  10. DIY

    DIY New Member

    Messages:
    153
    Location:
    Florida
    In the kitchen:A stacked washer/dryer is right next to the HWH,turn around and there is the kitchen sink,a finished 2x4 wall is just behind the kitchen sink where the bathroom tub/toilet and lavatory sinkv is that is It. Not a very long run of pipe at all. Could this problem be with the dip or anode tube at the HWH? Or, just with the 3/4" pipe on the hot side?
  11. Handiman

    Handiman New Member

    Messages:
    21
    Location:
    Nevada
    I wouldn't think 5' of 1/2" pipe would make any difference in heat delivery. How old is your WH? BTW: CWH would be more accurate than HWH (WH is the accurate term). If your WH is older than 13 years, you should probably consider replacement if not supplying ample heat. If GAS fired WH you should check the SOOT that is around the burner, I had a good amount in mine after nearly 20+ years. The anode rod wouldn't be cause of slow heat distribution, if really corroded you should replace for longer WH life. Dip tube wouldn't be a reason either. Also, is there a RETURN LINE for your WH?

    If fairly new WH and ample amount of heat output, you should consider a RECIRCULATNG PUMP for your WH. Easy DIY job for roughly $179.99 at COSTCO:

    http://www.costco.com/Browse/Product.aspx?Prodid=11026121

    LOWES and H O M E D E P O T sell as well.
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,892
    Location:
    New England
    a bad dip tube would cause the hot water to run out quickly, and probably not slow down the initial supply. There is always mixing of the incoming and outgoing water, the dip tube just forces that to happen more towards the bottom of the tank. Initially, the whole thing would be hot and it isn't a direct cross to the output.
  13. DIY

    DIY New Member

    Messages:
    153
    Location:
    Florida
    Handiman the WH is new as of 6/2008. It is a whirlpool 28 gallon capacity that is electric not gas. Jadanusha i guess I can check the dip tube easy enough. Seems that would be fairly easy enough to replace if needed. What would cause a dip tube to go bad on such a young WH? Thanks to both of you for your replys. p.s. who is right about the dip tube that may cause this...laughing
  14. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,892
    Location:
    New England
    It's unlikely the dip tube is bad. There were some defective ones used on some older WH, and so it comes up. I doubt you'd have that problem on a new one as they usually last the life of the tank.
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