Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

How long cool down before adding water to boiler

Options
itzasean
itzasean Member Posts: 71
in Strictly Steam
Hi due to the crazy cold and my old house the boiler has been non stop the past couple days. My question is how long should the boiler be off before adding water (if needed) to prevent any cracking? Also I hate to have the boiler off for too long because I feel like in the past once I shut it down for a while it takes forever for the system to heat up properly again?

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 23,313
    Options
    Steam, I presume? If you are not adding more than a gallon or two of water, and it is going into the wet return as it should be, 10 to 20 minutes is ample. Even if it going directly into the boiler, half an hour is enough.

    And you are quite right -- if you are near capacity (sounds as though you are) it can take quite a while to recover from a long shutdown. You don't need to.

    However. All that said. Just now much water are you needing to add? Even when things are going full song, you really shouldn't need to add more than a gallon or two per week. Any more than that you should be beginning to worry about leaks.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • GW
    GW Member Posts: 4,693
    Options
    I don't wait; just add it. We are talking steam right?.

    The only time one would wait is if the boiler ran out of water and it's 'extra hot'. Then kill the power and come back a couple hours later and slowly add. I've never seen that or done that; that's not a good day for the boiler.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • BobC
    BobC Member Posts: 5,478
    Options
    I've lived with steam for 70 years. When I add water I add it whenever I please, if the boiler is still hot or actively making steam I just add the water very slowly - it takes a full minute for the gauge glass to go up 1/2". By adding slowly you should not have to worry about shocking the cast iron.

    As @GW said NEVER add water to a hot boiler that may be out of water, shut it down and wait a couple of hours for things to cool and even then watch out for leaks.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • SeymourCates
    SeymourCates Member Posts: 162
    Options
    @itzasean

    You can add water to a steam boiler anytime you wish with no waiting, provide it currently has water in it.

    If you think about it, the auto feeders do exactly the same thing every time they sense a low water condition. So, any suggestion to wait a certain period of time would be not accurate.

    When you blow the boiler down and all traces of water are eliminated and the CI is at 215F, now you have to wait about 75 minutes (CI below 135F).

Categories