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Steam Trap Replacement - Time of Year

TBowers Member Posts: 2
We are going to replace the steam traps in an apartment building doing 1 stack at a time completely but was curious if the time of year matters such as doing during the summer when boiler is shut down or is it fine to in the winter when the boiler is running.


  • Jamie Hall
    Jamie Hall Member Posts: 18,672
    So long as the boiler isn't actually running while you've got things apart...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    JUGHNE Member Posts: 9,715
    Dan has written about changing traps during the heating season.
    You may get one floor done and turn the steam back on......then possibly old bad traps on another floor would pass steam into the return and ruin your new traps.

    Perhaps Erin has that story she could post on the wall.
    EBEBRATT-Ed Member Posts: 11,887
    What @JUGHNE said is correct. Better to wait for summer if you can
  • zoom
    zoom Member Posts: 72
    I changed all my traps this winter. I was mindful of the warnings against doing so, but despite the installation of a new boiler, many of the radiators were slow to heat (over an hours in some cases).

    Changing the traps, especially the cross over traps, made an enormous difference to the performance of the system. Many of the existing trap units were severely rusted, and some had been removed. I methodically went through and changed all the traps without any negative consequences, and many positive results.

    Changing all the thermostatic traps, improving the mains venting, and lowering the operating pressure to 6 oz (Vaporstat plus snubber) resulted in rapid, even heating radiators and lower fuel bills.

    I gradually came to understand the chain of events that had unfolded over the last 30 years. Failing radiator traps resulted in the traps being removed and the boiler pressure being turned upwards of 5 psi. The high boiler pressure caused water to back out of the mains vent, so someone blocked the vent air eliminator to prevent that happening. So now the system had cold radiators, failed traps, no mains venting, and higher pressure that as venting through the radiator supply valves causing continuous boiler water loss and dripping water.

    Took many hours and $1k+ in radiator traps but the results were well worth it.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,562
    Well done, and hopefully the fuel savings will pay for the cost soon.
    The important thing is you will now have comfortable heat throughout, and that is PRICELESS!—NBC