gurgling sound in hot water system

ChrisJ

A friend has a forced hot water system using a fairly new WM boiler and he recently noticed a gurgling sound, or a sound as if there is air in the system for 10-20 seconds after the pump turns on.  It sounds like water pouring.



The system seems to heat well and he has tried bleeding radiators several times and has not been able to get any water out of the system.



Any ideas?  I'm a steam guy my self and have never worked on a hot water system.

Mark Eatherton

You're a rarity...

Most people have lots of experience with hot water, but none with steam :-)



Just guessing that your friends pump is on the return, pumping towards the expansion tank connection, which causes air in suspension to ballon when it sees negative pressures produced by the pump.



Got pictures?



Welcome to The Wall.



ME

ChrisJ

return

Hi Mark,



Thanks for the response.  He says the pump is on the return but he is not sure where the expansion tank is.  He is going to get me a picture tonight when he goes home.

Steve Whitbeck

system pressure

Is at or near Zero

The system pressure should be at approx. 12 PSI.

No water from air vents on radiators means not enough water pressure in system to raise the water to that level.

ChrisJ

Ooops

I meant to say he isn't getting any air when he bleeds the radiators. He gets plenty of water and I'm sure the system is at 12 PSI.