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Shutoff valves on automatic feeds

Greg_38 Member Posts: 3
Should the shutoff valve be left open to the automatic feed on a hot water boiler after filling. If you have a run away burner (ie stuck gas valve) the boiler starts steaming, blows the T&P valve, pressure stays up, no water added, but when it is empty (and very hot), the pressure goes down, the automatic feed opens, and you have cold water going into a very hot boiler. Makes for a "boiler room disturbance".


  • Uni R_2
    Uni R_2 Member Posts: 589

    With a LWCO or flow switch there is no debate - leave it closed.
  • Ragu_5
    Ragu_5 Member Posts: 315
    Tough Call

    My old boss used to ALWAYS shut the feed valve off after the system was purged; however, we are required to use LWCO's here in Maine.

    In my experience, I must say that I have experienced more problems with a system overfeeding rather than underfeeding, and that shutting off the feed has been beneficial. Unfortunately, one has to follow the rules of The Authority Having Jurisdiction (AHJ) in order to be legal and non-liable. Ask your Insurance company.

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  • Darin(in Michigan)
    Darin(in Michigan) Member Posts: 90

    When anti freeze is in the system, we shut off the water feed to keep from diluting it in the event of a leak. If the customer is home all year round, we leave it on. Either way we tell customers to turn off the domestic water if they leave the structure unattended for any length of time.
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