Cleaning a Steam System

P Eddy

Have a one pipe steam system. 100 year old house - old piping system, but new (2 years old) boiler. I know the water gets dirty relatively fast. I try to drain the system pretty low and refill with clean water on a regular basis during the winter months. What else can I do to clean the system? The vents are hissing pretty bad these last few (really cold) days and I think the dirty system may be to blame.

Thanks all.

Dana

First of all, adding cleaner to a system that old may create more problems than you want to deal with. Secondly, adding fresh water to a steam system regularly is not necessarily a good thing. That fresh water has a certain Ph level, or acidity. that can cause more problems as well, especially as it gets constantly heated to a boiling point. I,m not a chemical engineer, but I believe this is correct. Hissing vents on a steam system is not a bad thing. They are hissing because the system is running and sending steam up to the radiators, which is how the system works. The colder it gets, the more the system runs. The boiler should be cycling on and of at about 1.5 psi on the gage. If the boiler is building more pressure than that get a proffessional out to find out why. Residential steam vents will only withstand about 3 psi before they rupture and stop doing what they're supposed to. Steam vents at the radiators on a system that old should be replaced about every 2 years. If they stop venting properly you will vent steam as well as air, which is not good. When the steam hits the vent, it should close and only open again after the steam condenses back to water, as the steam condenses, the water content increases, gets heavier and the vent then drops open to let the water out to go back to the main and the boiler and then let more steam in to continue to heat.

J.E.

one pipe steam , eh?

I live in an old brick victorian on the west coast of michigan. We have a single pipe paralell flow gravity system. I cant say that we have such an alarming amount of crud in the system, but I can say we used to have vent noise. See, when we moved in 2 years ago, we replaced the boiler and had the asbestos removed. We ran the system uninsulated, and with ruined main vents. - The heat was uneven, the vents hissed the pipes hammered... we were never cold, but we were never happy either.
Then we bought some of Mr. Holohan's steam books.
they are a great investment, and the information knoweledge and wisdom is nearly priceless. if you plan on being happy with your heat, there a must have!
-Then we wrapped our pipes with foil backed fiberglass batts, and fastened the stuff on silver side out with 10 inch zip ties every 16 inches on every pipe in the basement.
then we replaced the main vents (2 for about $80)
Uneven heat? Hissing vents? GONE!
as for the banging? i found that the pipe hangers were really loose, and corrected that part, and then i made sure that nothing was resting on or hanging from the steam pipes. a 3/4 inch galvanized water pipe perched atop a steam pipe will cause hammer, so i hung the pipe with a nail and a leftover zip tie. Hammering problem solved!
and then the pressure thing- our house is 2 storeis tall, and we set out pressure as 1/2 psi, and we never even make that! we make about 1/4psi (thats four ounces!) and the place heats like a dream. Nothing like a 400lb hunk of hot iron on a cold day.
J.E. Manistee County, MI

ta finnegan

Dirty water?

It may or may not be the water, especially if your vents are hissing.

You need to see if your piping tolerances are o.k., you also need to make sure the pressuretrol is cranked down. An oversized or overfired boiler could also do this.

Are the vents new? These things do not last forever, if they are 5 years or more, you should change them.

As for cleaning, it is best done in the summer in my experience. Each manufacturer is particular on how they like it to be done, follow the instructions!

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J.E.

another thought...

I remove my vents once a year and boil them for an hour in a big pot of water and and a and a cup of C.L.R.
vineger works just as well. i recommend doing this before tossing the vents, they are expensive and most of my vents are from the 1940's and still work like a charm.
THEY DONT MAKE THEM LIKE THEY USED TO, however the old vents like their annual cleaning, but the first year, of boiling the new ones, i managed to boil the chrome plating right off of them down to the copper - i was shocked! granted there is a weak acid and heat involved, and they look sort of cool after some brasso and carnauba wax,to keep -em shiny coppery lookin', but i would try this boil method first, before replacing them at $20 or so a piece
good luck,
J.E.

Robert O'Connor_3

Your insulation fix

J.E.: can you give me some additional details about your fix using batts to insulate the pipes? What type insulation did you use? Have there been any problems with the install? Did you debate over rigid pipe insulation before you went with the batts?

Thanks for the reply in advance!