Green water in the sight glass.

JcDc2017

I was on a service call for a steam boiler and noticed right away that the sight glass had a green tint to the water. The homeowner explained to me that the previous company installed an additive. He had no other information about it other than that. Aside from using something to clean the boiler would there be any reason for an additive?

Fred

How old is the boiler? Many of those green additives, like Squick, are cleaners that someone puts in to coagulate oils on the surface of the boiler water and cause it to fall to the bottom of the boiler but , eventually the oil molecules break away and float to the top again.. It's faster than skimming but not nearly as effective, if at all. I would drain the boiler, fill it and drain it again, fill it to the normal water line and bring it to a boil. If the water bounces a lot (more than an inch) or you see water droplets on the top quarter of the sight glass, the boiler should be skimmed. A slow but very worthwhile process.
Some people add a couple steamaster tablets to condition the water or something to balance the pH of the water but those usually either turn the water a pale purple or no color at all. I typically add two steamaster tablets at the beginning of the heating season but nothing else throughout the season.

JcDc2017

Fred,
Thank you for your feed back. I wasn't sure if an additive of any type was normal. And now that you say the Squick product causes the oils to coagulate and sink to the bottom, I do remember when I was testing the l.w.c.o. And feed some water back in there were some small little balls of muddy looking water kind of like how oil and vinegar looks when you shake them up. The boiler might be 10 plus years old. But thanks again I will follow up with learning more about the steam master tablets.

Fred

Has any of the piping been replaced/repaired more recently? New pipe will also have oils on them from the manufacturing process that will work its way back to the boiler as well. I am guessing that boiler likely needs a good draining/flushing and skimming. And, BTW, if you use the Steamaster tablets, use only two tablets, don't follow the directions on the bottle as they say to use a lot more and that causes foaming and a really unstable waterline.