proper way to skim a weil mclain peg45 steam boiler

norb

when skimming a steam boiler, should the thermostat be turned down to a low setting and let
the boiler cool prior to skimming? what is the right sequence in the skimming process?
also, when skimming and letting water back into the boiler, do you need to wait after allowing water
back in, for the oils to settle to the top OR do you just keeping filling and skimming continuously without
waiting inbetween? I am new to this and have a new boiler in need of a good skimming but I have never
done this before---thanks

KC_Jones

Do you have your manual for that boiler? If so the procedure that Weil Mclain recommends is right in the manual on page 25. That being said the basic concept is to fill the boiler close to the skim tapping. Then fire the boiler, but don't let it actually boil. Once you get it warmed up shut the burner off at the boiler with the service switch, which should be mounted on the side of the boiler. Then you open the skim tapping, then open the manual water feed just a tiny bit to trickle water into the boiler very slowly until you get a pencil size trickle (or even smaller) flowing out of the skim port. Do not stop the water flow, just let it go like that for several hours. I wouldn't judge it as Weil states by how dirty the water is, just let it go for several hours. After that close off the skim tapping and fire the boiler normally. The "test" if you have skimmed enough is the behavior of the water line in the sight glass. It should have a slight bounce maybe 1/2-3/4" or so, but no more than that. If it is bouncing violently you probably need to skim more. Don't count on getting it done in one skim. If there was much pipe replaced you will probably need several skims over time. Oh and I prefer using a bucket so I can monitor the flow more easily, but some people just let it go to a floor drain using a hose. That is a brief overview, I have attached a link to the manual in case you don't have it.
http://www.weil-mclain.com/en/assets/pdf/EG_Boiler_Manual_Series5.pdf

norb

I HAVE THE MANUAL AT HOME BUT COULD NOT FIND ANYTHING ON SKIMMING, MAYBE I WAS SKIPPING OVER IT.
THANKS

KC_Jones

lol...That's one reason I like the electronic files I can just do a text search for "skim" and find everything that way.

Fred

To add one additional point to what KC said, after skimming and closing the skim port, use the boiler drain valve to lower the water level back down to its Normal water level

KC_Jones

lol Thanks for that Fred!

norb

can the boiler be skimmed when all is cooled down? will it be effective to do it this way? I know most articles say to get the boiler hot , but not boiling, but I was wondering if this can be done when all the water in the boiler is cool, or not so hot?

KC_Jones

I think the idea of the heat is to help the oils "flow" onto the surface more readily, but cold skimming should remove any oil that is already on the surface. My gut says it can't hurt at all. Since the boiler has already been run for a while a lot of oil has probably been cleaned from the system and sitting in the boiler already.

nicholas bonham-carter

This method will cause the cooler makeup water to stay on the bottom, while pushing all the hotter water with the oil out the skimming port. Keep skimming, until the water coming out is cold. This should be getting rid of the majority of the oil.--NBC

norb

Thanks for the feedback guys.