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Atwood Water Heater

Discussion in 'Silverton Yacht' started by doorpro, May 1, 2011.

  1. doorpro

    doorpro Member

    Joined:
    Dec 15, 2007
    Messages:
    33
    Location:
    Long Beach, Ca
    Hi all,

    It's been a while and things have been going along great but recently the water heater on my now 10yo 453 started leaking and the darned thing is in a small access/attic area in the forward head and a bit of a pain to get to.

    So, i bought a new 20 gallon Atwood heater, the exact same model that came with the boat and proceded to remove the old leaky unit.

    Getting the thing disconnected wasn't to bad and to be honest re-plumbing it and conecting the power was very simple but i did come across one problem that i would like to know if anyone can help for future reference.

    So, I drained the old unit, well i thought i did and then proceded to slide it toward the access hatch but it was in there pretty good with no room to turn it round so that the open hot, cold and drain holes would be facing up when removing it. I even tried moving it to the port side across the access hatch but i didnt have enough room so back it went and i proceded to remove it with these connection ports open and of course i now know that i should have plugged off any holes before trying to move the unit.

    What happened next was that about three or four gallons of a slimy beige colored sludge came out of the heater and all over me, i was soaked from head to toe and of course i didnt realize that there would be so much so i just kept sliding the water heater down towards the floor and the thing weighs 50lbs empty and this one wasn't.

    Ok, enough of that because the new water heater went back in easily in less than 30 mins and was working with no leakage issues.

    My question here is "Why is the drain hole so high in the tank so that it's impossible to drain the water heater completely" but more importantly "Is there something that i should be doing monthly as a preventative measure to keep the three or four gallons of crap from forming in the bottom of the heater"?

    I should say that there were no indications of this sludge in the heater as the water always came out scaulding hot and clean but i would really like to know if there is something that I should be doing to keep this new heater clean.

    As usual any advise will be gratefully appreciated and I hope that everyone here is doing well.

    best regards,
    Doug.
  2. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    Yes, once a year drain the tank from the drain valve in the tank, this should help sediment from building up.
  3. doorpro

    doorpro Member

    Joined:
    Dec 15, 2007
    Messages:
    33
    Location:
    Long Beach, Ca
    Hi Capt J,

    the problem is that when you drain the unit and it appears to run dry there is still three or four gallons in the bottom because the drain plug is about 3" from the bottom of the tank so it never really drains so that it's completely empty.

    Even when my wife and daughter are aboard and drain the heater of hot water the sludge never gets into the pipes and of course as the heater is drained of hot water it is being replenished with cold.

    I was wondering if perhaps it could be flushed out somehow but i don't want to waste my time if the whole tank can't be emptied.

    regards,
    Doug.
  4. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,432
    Location:
    Fort Lauderdale
    Shut the water pump and the water heater breakers off, then drain it till it stops, turn the freshwater pump on, and the agitation of the water shooting in there should stir it up.
  5. Fireman431

    Fireman431 Senior Member

    Joined:
    Jan 11, 2010
    Messages:
    195
    Location:
    East central Florida
    Not knowing the specific design of the new tank, is it feasible to drill a 1/2" hole in the bottom (in a corner, away from any element) and place a rubber plug stopper or threaded/gasketed bolt for ease in future draining?
  6. K1W1

    K1W1 Senior Member

    Joined:
    Sep 30, 2005
    Messages:
    7,388
    Location:
    My Office
    Hi,

    Filtering the water you are loading is a good way to keep a lot of the mud and sludge out of the system, you might get quite a surprise in some places how brown the filters get in a very short period of time.
  7. doorpro

    doorpro Member

    Joined:
    Dec 15, 2007
    Messages:
    33
    Location:
    Long Beach, Ca
    Both great ideas and i had thought about installing a drain valve lower in the tank but then i thought that this might be to much agravation for a $600.00 tank that lasts 10 years.

    I think that I will start to filter the water coming aboard because although we do add a water conditioner to keep the water clean we never have filtered it.

    It does appear to me that Atwood designed the tank this way with a drain valve that only drains 75% of its volume so that the tank would eventually fail way before it should and they would get repeat customers every 8-10 years which is sad but thats the way that's the way the world has gone amd not only in marine products.

    Thanks everyone.
    Doug.