How do I clean a mud leg?

arches

The mud leg drain port on our boiler (Smith 28A) has a ball valve. When I open it with the boiler off or (carefully) with the boiler on, I get nothing more than a teaspoon of water. I saw reference to blowing down the mud leg by building boiler pressure with a king valve, but unfortunately this boiler setup lacks one.

Is it asking for trouble to try to manually clear the mud leg with a stout wire or metal rod? Backflush with a garden hose (after the boiler has cooled)? The boiler water is quite dirty, and seems to be getting worse. 

There's a drain cock at a low point in the wet return, but I wouldn't be able to drain the boiler below the height of the hoffman loop nipple.

jpf321

nudge

since i have no experience, i'd probably think it's ok to back flush it with a garden hose .. but i'd probably be wrong .. i hope someone has better answer.

nicholas bonham-carter

dislodging sediment from boiler

if it were mine i would get a big pan holding several gallons, and place it under the valve outlet. then i would get a long enough piece of stout wire, and try to push it in; being mindful of the width of the sections. i would keep my hands as far away from any rush of hot water as i could; and be ready to pull the wire out quickly, and shut the valve. once the flow was started. once the water is out then you can take off the valve and look inside, to judge how best to rake out the sediment. there may be a temptation to use a high pressure washer, but maybe not with rubber gaskets, only with nipples between the sections.

just be gentle with any probing on any rubber gaskets there may be between the sections. this might be a situation where some boiler cleaner [approved by the mfg.] could be used to boil out/loosen the sludge.

regular "blowing down" of the boiler drain should keep this under control for the future [not to be confused with the LWCO blow down].

don't forget to heat any new water up to the boil, to minimise oxygen infestation!--nbc

arches

Thanks for the advice.

I'll give that a try. It probably doesn't help that this is just a 1/2" valve (reduced down from a 4" fitting). Ideally the clog will just be in the valve body...but things are rarely so easy! More frequent boiler blowdowns will definitely be in order once I get the valve flowing again.