Water Heater Temp

Discussion in 'Water Heater Forum, Tanks' started by Mikeyboy, Jan 22, 2009.

  1. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,995
    Location:
    New England
    Almost all boilers are closed systems, and require the use of an expansion tank. Same is true of any potable water system that ends up being closed.
  2. GabeS

    GabeS Remodel Contractor

    Messages:
    294
    Location:
    Brooklyn NY
    Aren't all potable water systems closed systems?? But not all have expansion tanks. In fact I barely see them here in NYC on no water heaters.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,995
    Location:
    New England
    No, potable water systems in many places are totally open in the sense that water from the house can flow back out into the mains. Only when you throw in a check vavle does it become closed. A PRV has one, the utility may install one either in their water meter or as part of the installation either now or in the future. They do tend to replace the meters, and newer ones often come with a check valve, thus, some municipalities require an expansion tank to be installed so there isn't a rash of service calls when their T&P valves start leaking.

    [​IMG]
    T&P Valve looking at two sides.
    Last edited by a moderator: Apr 24, 2009
  4. kingsotall

    kingsotall Plunger/TurdPuncher

    I hate that.
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