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Closed Loop

H2_Oh Member Posts: 1
I have a oil fired boiler that I get domestic hot water and a hot water heat closed loop. To work on changing my pressure regulator,(a Watts 12-15 psi with a quick fill lever.) and my circulating pump; can I turn off my supply to pressure regulator and drain the closed loop while still allowing domestic hot water to operate. I do not know what the inside of the boiler is like; can the loop be drained of water, and the boiler be firing, with no damage to loop? Thanks.


  • EddieG
    EddieG Member Posts: 150

    Boiler must have water. You can isolate the return and supply, but boiler must be open to expansion tank.
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