Steam Boiler Cleaning Issue

BruceR

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I would really appreciate any advice I can get to this issue.<span style="font-size:12pt"> </span></span></span><span style="font-size:12pt"> </span><span><span>

I have a residential steam boiler that has a significant amount of sediment in the tank.  My water fill valve was leaking last year and ended up overfilling the boiler (to the point where the steam pipes in the house above were getting filled up with water).  I have since replaced the valve and drained out the excess water, however it appears that the water washed back into the boiler a lot of dirt/rust/gunk from the pipes.  Now my sight glass is getting clogged up very quickly (after only a few weeks of operation) and I cannot adequately monitor the fill level.  The boiler seems to be otherwise performing adequately as far as I can tell as an amateur.  <span style="font-size:12pt"> </span></span></span><span style="font-size:12pt"> </span><span><span>

The question is:  How can I correctly clean the boiler to fix this issue.  My local plumber has recommended that I get the boiler skimmed - however I thought that this would just remove excess oil.  Will this also get rid of rust/dirt/etc as well.  Or is there another approach that I should try to clean out the dirt?<span style="font-size:12pt"> </span></span></span><span style="font-size:12pt"> </span><span><span>

If skimming is the correct approach, is this something that a skilled amateur can do or should this only be done by the pros?  <span style="font-size:12pt"> </span></span></span><span style="font-size:12pt"> </span>

nicholas bonham-carter

dirty sight glass

sounds like the rust and sediment would be more completely flushed out from the boiler, using the drain valve, at the bottom of the boiler, and if you had a drain valve on the wet return, that could also be drained.

a floor drain would be handy to discharge into for this purpose, otherwise, get a lot of 5 gal buckets.

there are a couple of ways to go about this: every day for a week, after the boiler has been off for a while, to let the rust settle to the bottom; drain the boiler until the water runs clear [auto-fill turned or valved off, until the draining is complete, then back on for the refill]. 

maybe more than a week will be required. the alternative  would be to completely drain the boiler, and refill when cool.

close the stop-cocks, and take the tube out of the sight-glass, and use a small bottle-brush to clean it so you know the results of your labors!

i have a couple of old speaker magnets on the lowest run of my wet return to trap rust particles, but i am not sure how effective that is!--nbc

crash2009

Skimming and Blowdown

 techniques are easily learned.  The difficult part is to know what to open and close, what to turn on and off, and what to do if something goes wrong.  Show us a few pictures of the boiler and we will likely be able to advise you on how to do it.  Take pictures of all 4 sides, and crouch down for a low perspective.  Somewhere around there, there is a waterline connected to the boiler, it will have some type of shut-off valve on it, likely 2 valves, need a shot of that too. 

Do you have a floor drain? 

Skimming will remove the surface dirt such as oils, chunks of teflon, etc.

Blowdown will remove the sediment, chunks of metal filings, etc.

Here is a picture of what I got out of mine.  After my little toxic waste pit dryed up, I rolled a 1" magnet around in there to see what I could find.  Look at all those little chunks of steel stuck to the magnet.