surge or vacuum ???

raz

same boiler as my previous post ( dry return vent ??? ) i got the call as ... new install water pouring out of rads ... i got to the call and viewed the install every thing appeared to be correct ... except the vents on return ?? ... fired the boiler and with in minutes water surged heavily in gauge glass followed by a sucking noise and all the water disappeared into the mains and risers and out of the rads !!! after about a minute all the water returned to the boiler ?? i skimmed the boiler , flushed chemical to lower ph ,lowered water level , and down fired boiler so flame wouldnt lick the back of the boiler . the issue still continued ... well boss had me give it back to the installers so i never found out what the issue or out come was ... what could cause this kind of issue ???

gerry gill

what do you mean by

the water flew out of the rads? it squirted out the air vents??  did it do this from day 1 or just suddenly?  it sure sounds like dirty water or water with a heavy cleaning agent in it..what did the near boiler piping look like?

raz

flushed and skimmed

i skimmed boiler heavily and flushed pretty much all cleaner out of it . used both tappings on boiler into a drop header ... 2" supplies into a 3" drop manifold with two 2" mains ... piped correctly ... supplies and take offs not butting into eachother or butting into equalizer.equalizer goes from 3" run to a 3" x11/4 " elbow .hartford loop is 11/4 " and both dry returns are 1"

gerry gill

sounds like the piping is textbook,

so i would have to assume there is still some cleaning agent present..i've had some boilers drive me out of my mind until i actually opened the unused return tapping cap or plug, and go into the boiler with a homemade 'wand' connected to a garden hose and actually wash the boiler insides clean..

nicholas bonham-carter

Wild water

Not only can dirty water cause this sudden drop in the waterline, but also a horizontal pipe in the returns now just above the new boiler waterline. As the boiler begins to build pressure, the waterline in the returns will rise up 1.75 inches for every ounce of boiler pressure. If there is a horizontal pipe in this height of rise, it will absorbe/hide enough water in the system to trip a low water situation. The water will always come back, but it's temporary absence causes problems!

High pressure can also raise up the water in the returns enough to flood the vents at the top of the dry returns with squirting consequences. There are 2 evils plaguing steam systems which must be overcome: high pressure, and air in the system, which must be chased out like the raccoons from the garbage (quoted from another steam guru).--NBC