Residential Steam Boiler Noise

Jackp2

I have a GSA-150 steam boiler approx. 6 years old. It is making a disturbing noise when it starts up cold. It sounds like tennis balls bouncing around inside the boiler and then it stops when it starts making steam. What could be causing this noise? It is audible throughout the house.

Jamie Hall

It may be scaled up -- that is, mineral deposits on the walls of the boiler. They are pretty good insulators for heat, so in areas where they aren't, you get local boiling which can make odd noises until the whole things comes to a boil. You can hear the same sort of thing on a small scale in an old teapot.

However.

It's a little unusual for a steam heating boiler to get any significant scale, since the boiler uses very little water -- or should. Certainly less than a gallon a week, and often less than a gallon a month -- so there isn't much in the way of scale causing minerals.

Which then leads me to ask, how much water does your boiler use?

EdTheHeaterMan

The boiler water may have a layer of oily gunk on the top. this is making it difficult for the steam to boil thru.

After the steam begins to build and the noise stops, does the water in the gauge glass seem to bounce around a lot?

If yes, then the boiler needs to be skimmed. this will remove the junk that is floating on the surface of the water.


OR

The guys that turn the light on in the refrigerator are seeking into the heater and playing tennis.

Jackp2

Jamie / Ed, thanks.
I do not add water very often. So not an unusual amount. We did skim the boiler and it didn't seem to have a lot of oily junk on top.
I will add that I have used the Steam Clean additive annually since the boiler was new (approx. 6 years). I never used this before and never experienced this before. So I wonder if the cleaner is introducing something to the boiler? The site glass does show a muddy color.

EdTheHeaterMan

So the next time you hear the noise, Check the refrigerator to see how long it takes for the light to come on. If there is a delay, then it's the tennis came.

Jackp2

Has anyone had experience with cleaning a steam boiler with trisodium phosphate? Or sodium carbonate? Or sodium Hydroxide?

Any concerns about what these cleaners would do to the cast iron?
It is supposed to be used to remove scale buildup.

Jamie Hall

TSP is probably the safest of the lot, though none of them will attack cast iron. Because of its phosphate content, it may or may not be available in your area.

Both of the other two are strong bases. While they are not toxic in the conventional sense of, say arsenic, they are very dangerous to handle, and can -- and will -- kill you if mishandled. Not that they can't be used, but one must use tremendous care and full personal protective equipment if playing with more than a few grams.