Close radiators, pressuretrol, rumbling boiler...

RobLC

Any guidance would be helpful and appreciated.

Have vacant apartment, shut off 4 large cast iron radiators - - boiler (big, maybe Utica boiler) started to do this rough kind of rumble. So, I opened the supply valves to the closed radiator and boiler seems to be running smoothly.

During the "closed" valve period, I cleaned out the pigtail and called our Homeserve tech. He was very patient and listened to my explanation. He said I couldn't keep the pressuretrol on a .5 cut in because the boilers vibration would make the p-trol perform too erratic. He set it at 1 cut in 1.5 cut out. Said it would keep the boiler from short cycling.

If the radiators were turned off (4 of them) could they cause the gas fired steam boiler to behave erratically?

And with the p-trol all the way down to .5 cut in, could the threaded shaft vibrate out of the spring and cause the boiler to shake and vibrate?

Hope this makes sense.

Thank you

Jamie Hall

Well, 1 cutin 1.5 cutout is OK. And, honestly, with a pressuretrol it's probably not a bad setting.

Closing four big radiators shouldn't change the sound the boiler makes -- but it will almost certainly make it short cycle, as it no longer as well matched to the radiation. But rumble? I wouldn't think so. That sounds like a combustion problem.

On another note, though, how did you shut off the radiators? If this is single pipe steam, don't close the valves! Turn the vents upside down instead. Very few valves close steam tight, and when a little steam gets in there it will condense and draw in more steam and so on -- but the condensate can't get back out and will make all kinds of funny noises, if not outright bangs.

Also, might I point out that if there are pipes in those spaces which could freeze...

RobLC

Thank you, Jamie for your input. I shut the radiators from the supply valve at each radiator. It's a one pipe steam system. Also screwed the adjustment for the cut-in to like 3 or 4 to make sure the screw wasn't wobbling out. Then backed off slowly until the cut -in was .5.

Did turn the radiators back on last night and the whole system seems to running well. The Homeserve tech should be here soon to make sure nothing dangerous.

Our boiler, I believe is an old Utica. It has an Economite 400 burner that was installed in the 70s. Not all techs very well-versed in this burner. We've never had a problem.

I did vacuum like ash or byproduct from the combustion in the fire box. I thought it might be messing up the flame when the boiler was running. The flame still burns as good as it ever has.

Very interesting about turning vent upside down. First I ever heard, but I understand the principle - - makes sense.

Thank you for your help.