Hot water backflow

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by tanikir, Dec 4, 2008.

  1. tanikir

    tanikir New Member

    Nov 12, 2008
    If the hot water hasn't been used in a while and I grab the tanks intake it is just as hot as the output. I'm assuming there is some sort of backflow preventer to stop this energy loss. What should I do to fix this?

    If it matters, it's a kenmore tank built in the early 90's. There are no sweat connections near it so that couldn't have damaged anything.

    Is there any maintenance I should be doing to help this tank out. I really can't afford a new one and I would like this to last despite it's age. I looked through some threads but found conflicting ideas. Thanks to all.
  2. hj

    hj Moderator & Master Plumber Staff Member

    Aug 31, 2004
    Cave Creek, Arizona
    hot pipe

    It is a simple matter of physics. Hot water rises, and it doesn't care whether it is rising in the hot pipe or the cold one, and NOTHING will prevent it only slow the process down. It will only heat up to the point where the pipe turns downward at which point it will start cooling off.
  3. Sponsor

    Sponsor Paid Advertisement

  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    There are a couple of heat traps that are often included on new installs, could be retrofitted, but highly risky on an old WH. One type has a plastic ball in it to limit convection water flow. If you get some mineral buildups, they can stick and block the normal flow of water use. Another type has a flapper valve to close off the inlet and outlet. Eventually, they leak. They must be installed on the correct port, or you won't get any flow at all when you open a faucet.

    If you don't have any insulation on the pipes, you can save a little energy if you install some on the hot water pipes (somebody calculated about 13BTU/hour/foot of 1/2" pipe, if I remember right - it was in a Fine Homebuilding issue recently). Insulation can cut that, and keep in mind, not much of the pipe will be hot unless you are running the hot tap regularly, so the loss would taper off in between uses.
Similar Threads: water backflow
Forum Title Date
Plumbing Forum, Professional & DIY Advice Where can backwater/backflow valves be used in a building? Nov 29, 2016
Plumbing Forum, Professional & DIY Advice Concerning backflow [water contamination] issue, advice needed Oct 16, 2016
Plumbing Forum, Professional & DIY Advice Hot water backflowing Nov 3, 2015
Plumbing Forum, Professional & DIY Advice Are some checkvalves better than others - Water Backflow Preventer Sep 22, 2011
Plumbing Forum, Professional & DIY Advice Backflow valve on water supply for cleanout Nov 15, 2008

Share This Page