Boiler Noise?

alotlikeearl

Have a customer with a New Yorker CG50 cast iron, gas fired boiler.  Within about a minute of the burners firing it begins to make a sort of gugling/popping noise that sounds like the water is boiling.  Temperature of supply pipe off boiler is about 165 degrees.  The noise is only in the boiler itself not in any piping.  System has 2 zones of baseboard with circulators and heats fine with no noise in the baseboard.  Is it possible sediment could be causing the noise like sometimes happens with water heaters?  The noise continues for about a minute after the burners shut off. Ideas?

Jerry

Alan (California Radiant) Forbes

Boiler noise

What is the system pressure at the boiler?



It could also be that for some reason, water is not moving quickly enough past the heat exchanger.  With slow moving water, it picks up too much heat and starts to boil.  Check to make sure the pump is working properly and you have at least 10-15 psi of pressure.

alotlikeearl

Pressure OK

Alan,

Pressure is right on 12 PSI though the pressure guage does pulse while the burners are fired.  If the water was hot enough to boil, wouldn't I have more than 165 degree supply pipe temperature?

Thanks!  Jerry

Alan (California Radiant) Forbes

Noise

I suppose you're right. 



When does the noise occur?  Zone A on? Zone B on? Both zones on?



Alan

David Sutton_6

Sandcasting

i had the same thing happen with a boiler ( to remain nameless to protect the innocent ) the rep came out and said it was sand trapped in the boiler they said its happen few times before that knew of and gave us a new boiler,...Wa-La ..... no more sounds :-)



David

aka DrPepper

Mark Eatherton

I've had THREE different manufacturers with THAT problem...

Including one German manufacturer. I guess you could say it could be a problem.



It could also indicate an ongoing unseen leak, and subsequent lime scale accumulation at the heat transfer surface. Feel the makeup line where it goes into the boiler. If it is cold, it indicates fresh water (mineral laden) being taken on. If you suspect a leak, turn the make up water to the boiler off, and turn the boiler off, and if the water pressure drops to 0 overnight, then you definitely have a leak...



ME

alotlikeearl

Sandcasting

David,

Was your experience immediate with a new boiler or after a few years service?  This boiler is 10 years old and problem just recently began.

Thanks for the info!     Jerry

David Sutton_6

this was new

It was a brand new shinny boiler it started about 5 min after start up,



David

icesailor

It could also be

sand and other solid debris in the bottom of the boiler and when the burners come on, the debris traps water and makes it boil like what happens with domestic water heaters. Have you tried flushing out the boiler and trying to get any crud out of the boiler? It will act like low flow.

alotlikeearl

Icesailor

That's what one of our guys suspects but I just had never seen it happen in a boiler. 

icesailor

Boiler Noise:

I've seen it a lot. Just not to the degree you are writing about. It usually makes a racket after it shuts off.