How often should I flush Steam Boiler

itzasean

I have read mixed comments on how often I should flush out my Burnham Independence steam boiler. Some say as often as once a week, once a month, once a year etc. Some say flushing adds oxygen and minerals etc? Any suggestions and whats the best way to do this?

Steve Nichols

has it been skimmed?

I have a one year old Burnham Independence Steam boiler.  After I skimmed it and used a wand to really wash out the sections (Thanks for the idea Gerry Gill!), I haven't really touched it.

I don't know if you necessarily need to flush.  If the water in the sight glass is relatively clear and stable and no water is coming over the top and down into the glass, you are probably okay as far as eliminating most of the oil.

Being as fanatical as I am, I'll probably flush out at season's end and give it a good old washout with the wand (disclaimer: just a crazy home owner who loves steam).

Any fresh water added into a cast iron boiler will cause erosion of the iron over time so that is why it is recommended that the water be boiled after it is added--it drives off the "bad stuff" that can accelerate the boiler corrosion.

Just don't add cold water to hot boiler...that's a no-no.....

Jamie Hall

Don't do it

You need to flush the low water cut off, if it is the float type, somewhere between once a week and once a month.  The timing varies depending on how fast it gets gunked.  The purpose of this is to make sure that the gunk which gets in there doesn't get in the way of the float which makes it work.  The way to do this is to open its own drain fully, but briefly.  Do this several times until the water that runs out is more or less water -- it doesn't have to be clear, but it shouldn't be gunky.  A gallon or so should do it.



As to the boiler as a whole -- there is no need to.  Once a year it is probably a good idea to open the valves at the bottom of the sections and let them run a bit, to get accumulated gunk out.  A few gallons should do it.



Any more often, or any more, and you do introduce oxygen and, if your water is at all hard, minerals.  The oxygen will cheerfully eat away at the water side of the boiler and make leaks.  The minerals will cheerfully scale up the water side of the boiler and reduce its efficiency.  Neither is particularly desirable...

Sweet_Lou

How often should I flush Steam Boiler

Jamie

You seem to be one of the more knowledgeable people on this site and there are many really good people who add value to this site.  My Stam Boiler is new but my piping and cast iron radiators are very old, So I get a very big build up of very dark brown water when I flush about 10oz about twice a month in season (NY).  The 10oz I remove is the very dark brown portion and then I stop.

Any recommendations on how I could clean the entire system?     

Jamie Hall

Thank you...

Anyway.  Most of the real goop is probably in the wet returns, assuming you have them -- at least that's where mine seems to decide to reside.



This can be either moderately easy to get rid of, or a real pain in the neck; on the system I care for it's enough of a pain in the neck that I live with it.  If you are fortunate, though, and the system was installed or repaired recently by one of the real experts, it should be possible to isolate the wet returns and open them up -- valves are ideal!.  If you can do that, you can flush them out with a garden hose.  No problem, other than figuring out what to do with the gloopy water that comes out.



Dry returns don't accumulate much -- there isn't really enough water in them -- and steam mains accumulate hardly any.



Radiators do, most assuredly -- but it isn't going anywhere and doesn't interfere much with operation, so I wouldn't bother with it as the only way to get it out is to disconnect the radiator, move it somewhere where the mess isn't a catastrophe, and use a wand to get inside it and flush it.



The frequency and description of the flushing water you mention sounds about like mine.