Hissing and steam coming out of main vent

Pat_NYC

I just recently installed a boiler - actually two years ago.  The main vent was hissing and steam was coming out as though it was a sauna.  Is this normal?  we set the temperature at 78 degree -- could that have been the cause?



Another question - my new boiler is adding a gallon a day of water in the system ?  I cannot seem to locate the leak at this point.



Also, Dan - I love your book - " we got steam heat!" wished I bought it before I had it before hiring my current plumber who seem to be incompetent as they installed cooper pipes as they were replacing a leaking pipe.  That was not smart of me...wish I had your book earlier.

nicholas bonham-carter

like a sauna

it is not normal at all. the pressure is probably too high. the water in the boiler is probably just being allowed to escape, and therefore is being replaced by fresh water at such a rate so as to severely shorten it's life. if you feel comfortable with simple maintainance tasks, adjust the pressuretrol settings down to keep the pressure down below 1.5 psi. details vary based on which model of pressuretrol you have.

this may restore the main vent to proper function, or it too may need replacement. remember that you can never have too much main venting, but the radiator vents should be slow.--nbc