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problem with residential radiant system

I recently was called to service a no hw situation At the point & time of my arrival the client had been without hw for at least 3 days that I know of.. Upon arriving I found the system to be a radiant heat w pex tubing consisted of a Hw 3 zone gas boiler(crown) & a 20 gallon Electric Bradford & white hw storage tank w/ a aquastat.The client was getting no hw. I bled the system in 3 places, the boiler, the tank, & the riser found it was filthy & adjusted the temp on the aqua stat to 120 from 100 after bleeding the system  Hw started to flow again at least temporarily. Besides my personal opinion that.the storage tank is not a good fit in a 1 family house within Nyc confines etc. I suggested that a problem might exist with either the aquastat & or the element despite the fact that the system was no more than 2 yrs old .I personally walked away & strongly suggested to the customer that you get the original installer to service it. My question is for the future the correct possible diagnosis & solutions if I am incorrect


  • Alan (California Radiant) Forbes
    Not clear

    If it's an electric water heater, then it has nothing to do with the boiler, correct?

    Or is it being used as a storage tank, heated by a tankless coil on the Crown boiler?
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Greg Maxwell
    Greg Maxwell Member Posts: 212
    No Heat

    You are going to have to be more clear as to what is supposed to be doing what.
  • chabadplumber
    chabadplumber Member Posts: 11
    radiant system

    sorry for the late reply In re to the above. to my knowledge it looks like it is being used as  a storage tank Hence the aquastat.The system is a 3 zone radiant system with pex The way I understand  it & saw is the boiler sends the water to the Electric Storage tank & heats the house. The customer complained of no hw I drained the system partially including the tank & as happens many times the water heats up (at least the pipes get hot. I am not that familiar with these systems & personally would not put in a storage tank for hw. I would go with a Gas Hw heater (regular or tank-less any time especially in the confines of the city I simply wanted to know for future reference If my diagnosis was correct if not what the issues could be
  • Ironman
    Ironman Member Posts: 7,376
    Are you saying...

    That both the space heating and domestic hot water are coming off of the storage tank? If that is the case, then it's definitely wrong. And if the pex that's supplying the radiation is non-barrier, then that could be the cause of the sludge in the system.

    Please clarify the arrangement a little more or maybe post a diagram.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • chabadplumber
    chabadplumber Member Posts: 11
    reply to your question

    I didn't take any pictures.The way I saw it is the boiler fed the storage tank & also the heat & when I bled the system it was filthy.The system isn't more than 2 yrs old & I suspect there is a reason why the company that installed the system either won't service the system or the owner didn't or won't call them..I only looked at the system for 10- 15 min. & after bleeding the system walked away etc.
  • JStar
    JStar Member Posts: 2,752

    So, the electric WH is being used as a storage tank? Is it controlled by a zone valve, or a pump? We'd have to see exactly how it was piped and controlled to give any kind of advice.
  • chabadplumber
    chabadplumber Member Posts: 11
    reply re boilers

    The best I could tell It was definitely set up as a storage tank even a electric heater  has a pilot that is accessible this did not It was sealed with no opening therefore a storage tank.The piping from the tank may have gone to one of the zone valves I do not recall  their definitely was no pump
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    even a electric heater has a pilot that is accessible this

    I am not a professional, so I have not seen everything, and I do not have all the answers. I did do some electrical and electronic engineering in my professionial life, and based on what I know about that, I am mystified as to why an electric water heater would need a pilot. Would it not need a gas connection and a vent to operate? I have had several electric water heaters and none of those had pilots, gas connections, air intakes or vents. What need would it have for a pilot?
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