Water lose in steam boilers

fitterandy

I work on installing larger steam heating systems in NYC. I'm having a problem that I can figure out. Both boilers are loosing water and the boilers are not running yet. At the same time that I notice the boilers are loosing water, the condensate receiver is overflowing. In an attempt to isolate the problem I closed both feed water valves to the boilers and the flow of water out of the receiver stopped. The receiver is vented open to the atmosphere and above the water level of the boiler. The feed water lines to both boilers have 2 check valves (wafer style) in each line. They are in stalled with the flow in the correct direction. The vents on top of the boilers are also open to break and vacuum/ pressure issue.

JStar

Water

Check valves stuck open?

gerry gill

or,

they are made in China.