nervous breathing air vents

joecann

We just replaced my daughters steam boiler.  One year before replacement I updated all air vents and added main vents.  The system seems to slowly heat up.  If you listen to the air vents they sound like they are nervously breathing, irregular, pulsing of air.  It almost sounds like it is going in and out, breathing.

I am not sure if this is a problem or this is the way it is supposed to work. 

The sizing of the replacement boiler was checked by measuring the radiators.  This matched the size of the old boiler. The new boiler will fill the system with steam, it just seem slower than I was used too and the vents make a little more noise than I had noticed before.  Any tips?

Alan (California Radiant) Forbes

New Boiler

When sizing a new steam boiler, you have to add up the output of all the radiators and then multiply by 1.33 which is a piping and pickup factor.  That is, you have to include an additional 33% to heat all the pipes connected to the radiators.



As far as the "nervous breathing", there might be some water in the steam lines which may be a symptom of improper near-boiler piping on the new boiler.  Can you take some pictures of the boiler piping, particularly the header directly above the boiler and post them here?

BobC

How slow?

Perhaps they moved the mains a bit when piping the new boiler, make sure the mains still have the slope they should have to encourage water to flow towards the returns. It sounds like something has changed, does it still heat everything up ok - and how much slower is it?



Picyures of the boiler and the piping around the boiler would help us see whay your dealing with.



Bob

TomM

near boiler piping

i had a situation in my home, where i beleive the A dimension was correct, but the equalizer was piped improperly, sending lots of water back up the wet returns.  At the lowest steam carrying pipes, they were probably filling with water, and the lowest first floor radiators took forever to heat, and 'breathed' as such.  I didn't really figure it out, because the A dimension was correct, until i put in a new boiler with correct near boiler piping and equalizer. 



post some pics.

Dave in QCA

updated air vents

When you updated your air vents, what type did you install?  After the new boiler was installed, have you clocked the meter to verify that it is burner at the rate it is supposed to?

Boiler Talk

If it ain't steady, get ready!

If you say you just got a new boiler, you probably should consider having the boiler skimmed again.  I had something that seemed like breathing when I listened to the radiators before I skimmed the boiler several short times.  Back to you.  When its running does the water line move a lot say a few inches?  I bet you that is the problem. 



When I listen to my radiators, I can hear a difference between when the main vents haven't closed and after they've closed.  The escaping air is steady at each phase.  Ready to skim? 

ChrisJ

Skimming

As others have said oily / dirty boiler water will do this.  However, so will lack of insulation on steam mains.  I recall reading that lack of insulation will cause air vents to breath in and out.