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Brown Domestic Hot Water

A couple of years ago, a customer was having an issue with brown water coming out of his hot water taps, but clear water coming out of the cold taps. He has a 120 gallon stainless steel lined Viessmann Horicell,. We opened up the tank and basically pressure washed the inside with a hose. The problem went away. We were there for a bad blower motor today and he mentioned that it seemed to be starting again. Has anyone experience this with Viessmann water heaters, or any make for that matter? I ask because this isn't the only time we've run into this before. Last year, we actually replaced a Viessmann Vitocell under warranty for a similar condition. This one was ceramic lined. In this current case, I find it very hard to believe that the stainless steel is actually corroding or anything like that. Is it just that the water heater is basically a collection point for any debris and sediment that might be flaking off in the incoming water service and pipes in line to the cold water supply on the water heater? I'm going to go back tomorrow, drain the thing down and take the inspection port off, but in the meantime does anyone have any ideas on exactly what is going on? Thanks in advance.


  • hot_rod
    hot_rod Member Posts: 22,266
    It is true that stainless can corrode and rust, but doubtful to that extent. I would suspect the incoming water is picking up the rust, maybe high flow conditions thru the tank churn it up occasionally.

    I'm surprised V would warranty a tank for that condition?

    A Big Blue cartridge filter may prevent the incoming colored water.

    It may be wise to have the water tested, you never know what could be in the source water. Ask the residents of Flint, MI.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • AirborneTrav
    AirborneTrav Member Posts: 29
    The ceramic lined tank was actually corroding and flaking off- no evidence of that in the stainless tank. I'm definitely going to recommend a filter to them. I will also talk to them about testing the water. Thanks for the recommendations.
  • SWEI
    SWEI Member Posts: 7,356
    Dissolved iron precipitating out from heat and oxygen, perhaps?
  • Jamie Hall
    Jamie Hall Member Posts: 23,453
    What is the water supply? Is it a well, or is it a municipal supply? If it is a well, and it has moderately high iron -- not unusual -- that iron may be in the dissolved form (called ferrous) in the water from the well, but if it sits for any length of time at all -- such as in a water heater -- it can oxidize to the ferric form, which would do what you are describing. Testing for dissolved iron isn't that expensive -- there are labs pretty much everywhere which do it -- and if it turns out that that is a problem, it's not hard to treat.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England