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Question about bleeding Lochinvar Noble radiant

Novaman854 Member Posts: 9
I am almost ready to bleed, then fire up my Lochinvar Noble 110 combi. On my system, my radiant feed's come out of the boiler, up a few feet, then back down to connect to the manifolds. Did I set myself up for problems getting the air out? I have attached some pictures. Any advice is much appreciated!


  • Zman
    Zman Member Posts: 7,569
    The up and down should not be a problem. I cannot tell how the rest is piped from your pictures. Normally you set it up so that you can close a valve to isolate the supply from return and then power purge using the system fill valve.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rod
    hot_rod Member Posts: 22,120
    A fill valve with a fast fill function can help purge systems with high points like that. If you can isolate that loop and get a good 3-5 gym flow rate through it you should be able to push air out of any high points.
    A 12 psi fill and the circulator alone will not generally purge air sufficiently. Some installers will add a coin vent or auto vent at high points. Is this the only ups and down?

    Looks like a swing check on the autofill, a back flow device would be a better option, even on a private well system. It would better protect from the potential of boiler water entering the well water system.

    Also, it looks like two DWH expansion tanks? If one is being used for the heating side, be sure it is pressurized properly.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream

  • 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