Backwashing a geothermal heat exchanger

Discussion in 'Maintenance and Troubleshooting' started by LT1Pat, Dec 15, 2010.

  1. LT1Pat

    LT1Pat New Member

    I installed an open loop geothermal 4.5ton system with a cupronickel heat exchanger in my home last year. I used two "EBV" taco valves which were given with the system but also knew they weren't ideal for the open loop. The other day I went to check on it and noticed that the second stage was sticking and using the little knob I was able to manually open it. After that it seems to open but for the future would the Taco "Geothermal" valves be a better option? I don't know how well those hold up to the hard water buildup compared to the EBV style.

    My system has been running for a little over 2 years without being cleaned yet and I looked at the drain pipe and there is a thin layer of iron/gunk build up and I was wondering the best way to backwash the system. It will sitll peg the 10GPM flow meter if I open the valves all the way but I don't know if residue in the heat exchanger could be making the system run less efficient than it could be. When I bought the system the person I got it from gave me a gallon of "acti-klean" and the directions state that it's to be used on the outside of the coil. I was planning on filling a 5gal bucket and putting a 55gpm pump in there to circulate the water but I'm not sure how long I should leave it running and if the chemical is the right stuff to use.

    In summary:

    Should I backwash the system even if it's flowing enough water?
    Should I replace the EBV valves with the Geothermal taco valves?
    Is the chemical (pictured below) the right stuff to use in a diluted solution?


  2. geome

    geome Member Forum Leader

    The way your picture is linked gives people access to 800+ pictures. Just wanted to make sure you knew.
  3. LT1Pat

    LT1Pat New Member

    Thanks! I had my album set to private but I didn't know that that could be bypassed with that sort of link. Someone would be bored to death if they wanted to look at 800 of my photos though.

  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Coil cleaner is not the same thing as heat exchanger cleaner
  5. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    slow closing thermo-plastic or resin irrigation zone valves are waaaayyyyy cheaper and last a lot longer.

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