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Mothballing Radiant Heat System

SFNMJack Member Posts: 2
I’m going to shut down a radiant floor heating system. I’m wondering what the best way is to mothball this thing to preserve it for future use, possibly 24-36 months down the road. I know the water in these boiler systems and the associated in floor piping can be very acidic damaging tubing, valves, pumps and the boiler. Our water is also very hard with mineral deposits commonly forming on faucets. Is there something one can do to protect these components while the system is not in use but still allows for the system to be brought back on line with relatively little investment in labor or materials.

Any information appreciated…


  • Jamie Hall
    Jamie Hall Member Posts: 22,941
    What is the pipe material? If it is plastic, your best bet is going to be to empty it completely and blow it out thoroughly with compressed air. However, if it metal, it will be better to drain it and flush it completely and add back water (with glycol, if there is even a chance of freezing) and a corrosion inhibitor.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Is your floor piping copper or PEX?

    Rhomar PRO-TEK reduces corrosion on copper systems. Fernox also has corrosion inhibitors.


    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
  • SFNMJack
    SFNMJack Member Posts: 2
    It is Entran2. Not as bad as Entran but not the best for sure. No one ever made a claim on it for the Goodyear class action for this home. I’m second owner. It’s 26 years old and has not failed yet and I’d like to keep it that way. We have a Mitsubishi Mini-Split with a MXZ-SM48NAMHZ 48K BTU hyper-heat heat pump being installed with 5 FS heads as we speak. I have 10 kWh of solar that runs my house and 2 electric cars so we plan to migrate to the mini-splits to take up the rest of the capacity but want the radiant for backup when/if needed. We needed A/C anyhow so we decided to make sure we could heat with the splits as well given the nature of the tubing that is in our floor. We’re in Santa Fe, NM so we expect the splits and the hyper heat condenser to handle our winters well.

    Thx for the info
    Alan (California Radiant) Forbes
  • hot_rod
    hot_rod Member Posts: 21,872
    One issue with early Entran is the plasticizers come out of the tube, in some cases. I would not flush the water unless it has turned to sludge.

    Flushing it can lead to its demise.

    There was a project where an attempt was made to add plasticizers back into some systems. But by the time the systems showed leaks the tube was often brittle and cracked. Beyond the help of additional plasticizers.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream