Hot Water in the cold water pipes

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by dvandruff31, Jul 7, 2013.

  1. dvandruff31

    dvandruff31 New Member

    Messages:
    3
    Location:
    Los Angeles
    When I use the hose or sprinklers outside, the faucets (double handle) Shower (single handle) and toilets start getting only hot water going through them. Nothing in the system has been changed, this problem just kind of came up. Can anyone give me some in site into why this has occurred and what I can do about it?
    Thanks so much
    David
  2. Smooky

    Smooky Member

    Messages:
    623
    Location:
    NC
    Sounds like you have a cross flow somewhere. Do you have a washing machine “Y†mixer hose? Is there hot and cold water at the outside hose bibb? Turning on both hot and cold at the spigot and having a nozzle turned off at the end of the hose can cause a cross flow. Sometimes shower valves can malfunction. Do you have a hot water recirculation pump?

    http://www.toolboxsupply.com/y-water-mixer-with-hose-3-8.html
  3. dvandruff31

    dvandruff31 New Member

    Messages:
    3
    Location:
    Los Angeles
    The hose bibb is only cold and the washing machine to my knowledge has no "Y" mixer hose. Unless the Y is inside the machine and you're unable to see it on exterior. No recirculation system, just the regular old 45 year old standard plumbing. The shower valve is 6 or so years old. Could it be the problem even when it's not running and turned off? It's very frustrating as this only started to happen 6 or so months ago. I really do appreciate your assistance.
    David
  4. John28

    John28 Member

    Messages:
    34
    Location:
    PA
    Is the hot water just for awhile, then turns cold after running a bit? If so, it's possible water lines somewhere could be absorbing heat from a source when sitting stationary. Or if lines are exposed or within a cavity where the sun shinnes directly on them can heat it up some like a greenhouse effect?
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,059
    Location:
    New England
    Some single handle valves can allow a cross-over between the hot and cold when off (not all). If it allows it, try turning the handle to full cold and see if you still have the problem...if so, you've identified the problem child.
  6. dvandruff31

    dvandruff31 New Member

    Messages:
    3
    Location:
    Los Angeles
    I don't believe it's absorbing heat, it's under a raised floor and the water is hot, not just warm. Honestly, if the spigot outside is on and the faucet inside is already hot I can't get cold water out until I turn the spigot outside off. My biggest concern is that the toilet is going to crack.
  7. Smooky

    Smooky Member

    Messages:
    623
    Location:
    NC
    Do you have access to the water lines to the shower valve? With no water running anywhere in the house all water pipes should cool down to room temperature. But when you run a cold faucet such as the outdoor spigot it will suck the hot into the cold if there is a cross flow. If the cross flow is a the shower valve the hot will flow into the cold at that location and then both water pipes at that location will become hot. If you turn off the cold spigot and go run a hot water faucet somewhere else in the house the shower valve should start to turn cold because the hot water has less pressure and the cold water will began to cross into the hot water . If you can hold on to the pipes before they go into the valve you will be able to feel if the pipes are getting hot on the cold side or cold on the hot side. The shower should not be on during this test.
  8. mikeplummer

    mikeplummer Plumber

    Messages:
    190
    Location:
    Ontario, Canada
    could be a broken dip tube in cold supply to water heater. turn the outside hose on and see if the cold feed into the tank gets hot, if so it is pulling hot water directly through the tank and not a cross connection further down...if the lines are accessible so you can trace them it is easy to find your problem.... run a cold tap with hot water coming out of it (your problem scenario) then follow the cold supply from that point backwards along the cold supply and see where it turns from cold to hot and that will tell you where the problem is occuring
  9. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,689
    Location:
    Cave Creek, Arizona
    Broken dip tube would NOT cause that problem. If anything it limits the amount of hot water you get.
Similar Threads: Water cold
Forum Title Date
Plumbing Forum, Professional & DIY Advice, Tips & Can anyone explain this cold water shutoff valve phenomena Jul 30, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Hot/Cold Water crossover Jun 28, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Low Cold Water Pressure in Entire House Jun 18, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Hot water coming out cold faucet all over hotel May 27, 2014
Plumbing Forum, Professional & DIY Advice, Tips & Hot water at cold tap: questions about recirc pump, sprinklers, and check valves May 5, 2014

Share This Page