Steam Radiator/Boiler Sizing

michael_15

I have a problem with one out of the 5 steam radiators in my house squirting a lot of brown rusty water. All of the air vents hiss loudly. There are no main vents. Old house (>100 years). The problem radiator is the second largest; the length of piping to each radiator is roughly the same (the boiler is right in the middle of the basement and the radiators line the walls of the house). Radiators/boiler system is on the second floor only.

In any case, I'm trying to pin down the problem. First thing I noticed was that the radiator was completely flat. I shimmed up the side of the radiator, but this hasn't solved the problem.

Could it just be that I have a defective air vent? Out of stupidity (that's the only reason I can think of why I did it), I took the air vent off and held a paper towel (to catch steam) next to the hole and turned on the system. After a while, when the radiator was about halfway heated, large jets of rusty water (not hot, just warm) came shooting out. A lot. Probably over half a cup in the span of 2 seconds before I plugged the hole and turned off the steam supply to the radiator.

Should I get bigger air vents for my bigger radiators as well? I figure I'd need main vents, perhaps esp. so since it's a second floor heating system and, well, there are a lot of mains, but I'm looking for a fix to allow me to at least have heat in this room before I can get that fixed.

Oh, and another thing. I looked up some tables and have determined that my radiators are in aggregate rated at 167 square feet or so. I'm not sure I did my calculations right (it's heating around 800 square feet of living space), but in any case, I went down to the boiler (which is <2 years old -- the previous owner put it in) and it said "input: 105000 BTU" or something thereabouts, along with I think a square foot rating of about 275. Is this overkill? Is that a source of problem as well?

Thanks,

Al Letellier

steam problems

Sounds like a combination of bad rad vents and too high a pressure on the boiler, or possibly plugged or partially plugged returns. the boiler rating seems OK. There aren't too many steam boilers out there with a rating for steam under 300 sq ft. Could be the boiler is simply making steam too fast for the vents to handle. Sounds to me you need a pro to check everything out. The nozzle may have to be downsized and the pressure adjusted, along with some venting work. Not a DIY job.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"