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Should I have a Descaling Filter for Radiant Floor Heating?

I am about to have a bunch of work done on my radiant floor heating system. In a YouTube video I watch, it was recommended that a descaling filter should be used. Since our water has a very high mineral content, this seems like a good idea to me, and I just wanted to see what some experts here think of the idea?

I have 12 lines/loops (8 in my basement and 4 in my garage). There is glycol in the system which does get slowly diluted over time. As part of the new work being done, a pressure gauge will be added to each line -- I don't know if I have any leaks but this will help be isolate these lines.

Although I know very little about these systems, I would think that in a closed loop system there should be very little demand on the system from the water intake -- unless of course there is a leak. I do also have glycol in the system. The company also suggested that instead I could remove the reliance on the water supply to keep my system topped up, and instead install an Axiom DMF150 glycol tank which would keep the system topped up with glycol. However then I wonder if the fluid concentration would get too rich over time with too much glycol -- I suppose I could always add some water into the glycol tank then?

Sorry to go off topic there, but I'm mainly just looking for feedback on a descaling filter -- and any links to recommended filters would be great. Any further education you are willing to share on this subject would be greatly appreciated.


  • Jamie Hall
    Jamie Hall Member Posts: 22,175
    Snake oil. Fill the system to begin with with deionized water and your glycol mix and don't worry about it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • hot_rod
    hot_rod Member Posts: 20,826
    Find and fix the leaks! The glycol should not be getting deleted unless fill water is being added somehow?
    Consider a fill tank for the system to monitor how much fluid is going in.

    Use premixed glycol or deionize the water you mix glycol with. If not, hard water will ruin the glycol quickly.

    A Ph tester is also good to have, check it on a yearly basis. It starts out in the 10- 11 Ph range. If it drops every year, something is going on that needs to be addressed.
    Once it drops into the 7’s it needs to be flushed, system cleaned and a clean glycol refill.

    Do you absolutely need glycol in the system? It can be a costly and problematic fluid to maintain.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream