Flushing a Hot Water Tank and leaving it off for extended periods. Good Idea or Not?

Discussion in 'Shower & bathtub Forum & Blog' started by johnfrwhipple, Jul 21, 2013.

  1. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

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    3,939
    Location:
    North Vancouver, BC
    I'm doing some work out on Galiano Island here on B.C.'s Sunshine Coast and noticed a strange noise coming from the Hot Water Tank. I have never heard this sound before from any Hot Water tank and it was kind of a Whirling Sound. The hot water tank is an electric John Wood JW50SDEB1 (twin element).

    [​IMG]

    Manual for this model

    [​IMG]

    Manual for this model


    I thought that perhaps there was a leak in a water line and tried shutting off the cold water supply but the noise continued. When I used the sink a lot of sputtering happened and I chalked this up to the home's Bunk House (Detached Building) just not getting any regular action. The cabin and bunk house are four years old and everything is brand new back when it was built.

    I read through the instructions for the Hot Water tank and it says these sounds can happen when the hot water tank is not used very often. Should I warn the client of a potential problem?

    My gut tells me to flush the hot water tank and leave it be. I'm going to try and drain it as well with a garden hose and think perhaps I should just leave the hot water tanked switched off since this bunk house gets little use. What is the longest time a hot water tank should be left powered down? If it is say powered down for 4 months at a time should it be reflushed before use once powered back up?

    What about some kind of timer? Would a timer that switched on for say 4 hours every week be better than leaving the bunk houses hot water tank shut off completely for months on end?
    Last edited: Jul 21, 2013
  2. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
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    Smell from Hot Water Tank - Very strong after flushing the hot water completely.

    I finished flushing the Hot Water Tank and did this by simply running the sink and shower at full blast on hot water for about 20 minutes. I went back to the Bunk House and there is a strange odor - almost like sulfar or rotten eggs. I would think it was natural gas but the home and bunk house use electric heat not gas.

    I have smelt this smell as well while using the cabin but the smell is intensified in the bunk house after flushing this tank.

    Any connection here between the sounds and the smell?


    JW
  3. Terry

    Terry Administrator Staff Member

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    That could be from the water.
    Is it well water?
    I don't think you have anything to worry about. There are a lot of seldom used homes with electric that are only used at random times.
  4. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

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    Location:
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    [​IMG]



    Thanks Terry.

    I could not drain the tank but did hook up the hose and flushed it a second time with the water running out the hose and into the yard. The home here is hooked up to the local water source and it is not a well. I did not notice any sediment or crap in the water when I flushed it with the hose.

    So you think I should leave the the hot water tank on or off?

    Would adding in a bleeder valve be something like it be something I should do at a later date? So the tank could be drained fully and then refilled with ease?

    Would this help any?

    JW
    Last edited: Jul 21, 2013
  5. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
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    What is this fitting for?

    [​IMG]

    [​IMG]

    Terry I'm reading this manual and it says that an odour can come from the hot water depending on the location. Especially if the local water has a little sulphur. The manual recommends draining the system completely which I guess means I need to get a little air into the lines above which means coming back with fittings and a torch.

    It also says the hot water tank might need a new anode rod made from aluminum and not magnesium. How hard is it to replace this fitting? Is it worth the expense or is it cheaper to just change the entire tank?

    It also says in certain circumanstances chlorinating and flushing the water heater may be required.

    JW
    Last edited: Jul 21, 2013
  6. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
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    Extended Non-Use Service Warning on John Wood Hot Water Tank

    There is a bolded section in the manual that cautions against extended non-use. It refers to periods of time over two weeks and quotes that

    Hydrogen gas is extremely flammable and can ignite when exposed to a spark or flame

    It says that there will be sounds of air escaping if present.

    This is something we have heard and I'm worried about.

    I will be for sure contacting the dealer about upgrade information for this bunk house hot water tank and the one for the main cabin.

    [​IMG]
    Last edited: Jul 21, 2013
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
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    Location:
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    I have seen the warning, but have NEVER seen it happen. The odor is often a reaction between the magnesium anode rod and the water, especially soft water, which is creating magnesium sulfide, (rotten egg odor). It will also often leave black flecks in the bathtub which cause streaks if you rub/slide them with your finger. The "Thing" is a vacuum relief valve which is to protect the tank from 'implosion" when drainage or siphonage occurs.
  8. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
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    Location:
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    Thing-a-ma-do-bobber

    Thanks H.J.

    lol - Good thing I did not call it a Thing-a-ma-do-bobber
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