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Removing scale..

Timco Member Posts: 3,040
edited March 2018 in THE MAIN WALL
Customer has a HTP EFTC combi Boiler. The Water report is like 1000-2000ppm dissolved minerals and is very hard. In 18 months of service the 3/4” CSST coil (holds 15 gal in the coil) is down to 1.07 GPM through the coil.

I used 3 gallons of Flow Aid (one gallon then tried two) and it only reacted for 10-15 min then just circulated mostly clear fluid. Just bought 2 gallons of Hercules brand scaler and will try that.

Any other suggestions? Pump it in reverse flow? I’ve installed a Nuvo Manor softener and a good filter in-line but the damage is done.

Thanks. Tim
Just a guy running some pipes.


  • hot_rod
    hot_rod Member Posts: 22,246
    I think you are on the right path with de-lime chemicals. It may need to run for a few hours to do a thorough job. I suspect that corrugated tube may be harder to de-lime with all the ridges surface?

    Keep in mind it is a very thin walled tube, too much acid may pin hole it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • lchmb
    lchmb Member Posts: 2,997
    a co-worker just ran vinegar through a rinnia for two hours and then had it start leaking after completion.. I've used Fernox DS-40 on HTP to descale them but that was boiler side.. I would contact Emerson Swan and see what they recommend..
  • bob eck
    bob eck Member Posts: 930
    What about installing a product that Field Controls has called the Clear Wave. www.fieldcontrols.com look under products then under water treatment. This unit is supposed to be a descaler.
    Anyone using this product? Does it work?
    What about Watts OneFlow units? This unit is also a descaler.
    Anyone using this product? Does it work?