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Draining the returns annually, why?

Brad White_9
Brad White_9 Member Posts: 2,440
you are getting rid of, but the mud (congealed particulate free iron, dirt and oh, <i>there</i> is where they put Jimmy Hoffa....)

The water is just the transport system. The "mud" is prone to clogging the drain valves, LWCO and other devices, preventing them from working when you need them most. This kind of draining is a small price to pay.

Older boilers, the pork-chop kind, had or have what are known as "mud drums" along the sides for collecting this crud in a safer place.


  • Adam_24
    Adam_24 Member Posts: 36
    Why should we drain the returns annually?


    I am reading about installs that include valves to allow the returns to be drained annually without emptying the boiler. Could someone explain to me what is the benefit of draining the returns? Why do you want to do it without emptying the boiler?

    Are the returns returning distilled water from the radiators to the boiler? If so, it sounds pretty clean to me and if you are only just flushing more water through them every year, how can that be better than the water going through them all the time? What is it that is accumulating, rust? Are you using chemicals to flush the pipes cleaner?

    If you are just flushing water, with maybe some rust in it, I can see how it could just drain with a hose into the lawn in the yard, but if you are using chemicals, this would be a problem to me, of where to drain it.

    Thanks :-)
  • D107
    D107 Member Posts: 1,799
    you can drain into sewer/waste line, not backyard

    (HO here. I had mentioned to you draining returns w/o draining boiler but I indicated I wasn't sure of the exact procedure that we were advised.) Hopefully you'll hear from steam people on this or your contractors. (this was an apartment building with a big boiler.) We had a shutoff valve a few feet from the main return leg into the boiler for isolation purposes. If I recall in the return cleaning process they had to be filled and drained two or three times before they ran clear. I believe you'd want to get the boiler and returns cleaned on the same day, so that the chemical additive they put in will neutralize all that new water you just put in as soon as possible. But you'll hear from the experts or your contractors.
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