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Disconnect hydronic loops, but keep using bouler's DHW coil

eddoeddo Member Posts: 12
I'm replacing an old boiler with a combi boiler. I'd like to disconnect the hydronic loops so I can attach them to the new boiler, but since it'll take me a few days of part-time effort to complete the work I'd like to leave the DHW connected to the old boiler till the last minute. Is there anything wrong with that? No water in the boiler, just the DHW coil, or if that's not a good idea, any options for me?


  • GBartGBart Member Posts: 753
    make damn sure the expansion tank is still connected to the boiler you're running
  • STEVEusaPASTEVEusaPA Member Posts: 4,142
    You need water in the boiler, a working pressure relief valve, and the expansion tank connected as @GBart mentioned.
    I'd also disconnect the thermostat wires
    delta T
  • eddoeddo Member Posts: 12
    Thanks. So if I simply cap off the supply and return and keep everything else in place I should be good? Of course I'll make the boiler is filled after cutting those lines and capping them.
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