Water level rises when boiler starts steaming

Dave_4

I have a 77 year old one pipe steam system, with a 17 year old boiler that has two mains. For a while now I have occasionally heard a noise in the shorter main that sounds like water boiling. Also of note is that this short main runs into a crawl space that currently has no access. This main returns to the basement as a dry return and then drops to the floor level. I have replaced all pipes in the basement area but have not tried to break through into the crawl space. Recently I have had a problem with rads on this main spitting water out the vents (TRVs) and also bubbling/gurgling at the vent. Now I have noticed that when the boiler starts to steam the water level in the glass rises up about 2 1/2 inches. Should I expect that I have a problem with a clogged dry return, or a sagged pipe, or something else?

Unknown

Mel,

It sure sounds like your throwing water up into this main. When you replaced this piping(I assume it was a lot), did you "skim" the boiler? The "impurities" from the new piping sound to have found their way into the boiler and is causing your level to rise/surge.
BTW- How did you make-out finding the correct vaporstat number?
Dave

Dave_4

Thanks Dave. Since I have changed a lot of piping (all wet returns plus added a drop header), I did have to clean thoroughly by skimming and flushing. It seeems pretty clean to me right now. Also, I am having no similar problems on the second main, which led me to believe it was other problems. The way the water level rises when steaming starts just seems like the water does not return until there is some pressure to push it back into the boiler. Would this fit with a clogged dry return or with a sagged pipe? I sure don't look forward to breaking through a concrete block wall. Regarding the Vaporstat for replacement, I have been in touch with Honeywell, their local distributor, and two retailers, over the last two days. Have yet to get a good answer. By looking at the data sheet, I think I probably need L408J1009 (0-16 oz.) or the L408J1025 (0-4 psi.) Vaporstat. Any insight here?

Unknown

Mel,

> Thanks Dave. Since I have changed a lot of

> piping (all wet returns plus added a drop

> header), I did have to clean thoroughly by

> skimming and flushing. It seeems pretty clean to

> me right now. Also, I am having no similar

> problems on the second main, which led me to

> believe it was other problems. The way the water

> level rises when steaming starts just seems like

> the water does not return until there is some

> pressure to push it back into the boiler. Would

> this fit with a clogged dry return or with a

> sagged pipe? I sure don't look forward to

> breaking through a concrete block wall.

> Regarding the Vaporstat for replacement, I have

> been in touch with Honeywell, their local

> distributor, and two retailers, over the last two

> days. Have yet to get a good answer. By looking

> at the data sheet, I think I probably need

> L408J1009 (0-16 oz.) or the L408J1025 (0-4 psi.)

> Vaporstat. Any insight here?

Unknown

Mel,

I think your right(but not sure), with the L408J1009 control, the "1025" seems to have the "B" terminal omitted so it "makes" on pressure rise and that`s not what you want. Anyway,,,I wouldn`t think the dry return is clogged, but on the other hand, how is the venting on this main?, you say the main returns to the basement then drops below the floor, so I would be inclined to look at that before breaking any walls. If the piping was "sagged" somewhere, it would hammer like crazy when the steam hits-it. "Spirting" at the vents, tells me something else is the prob.
Dave

Dave_4

I put a Gorton no. 1 on this short main. Plenty of venting. I should have said the dry return enters the basement and then drops down to floor level. The vent is at the end of this dry return. Maybe it would be worthwhile to disconnect the elbow and try to look/probe into the dry return and see what is there.

Dave_4

Well, today I took off the Union near the dry return and the elbow, so I could get a look into the dry return. Surprisingly, after 77 years, it was pretty clean. Nothing that would account for my problem. I could see to the end of the return, which was about 6 ft. Then I put a fish tape into it and managed to turn the corner and run it in another 10 ft., with no obstruction. I did find that one of the radiators on this main was pitched the wrong way so I corrected that. I'm sure it was retaining quite a bit of water. Sometimes I think my boiler system has evil spirits. Maybe I need an exorcist. LOL. More later.