Vent-a-Palooza - all new, all leaking water vapor?

307TurboFire

Should brand-new vents be leaking enough water vapor to leave fog on a mirror, about 50% of the time, in the middle of a heating run?

After returning a bunch of no-name vents, I assembled a small fleet of relatively expensive vents, to have a sort of vent-off. I tried five different brands to assess what they are all like. They range from more-expensive-than-the-Big-Box-store vents to really quite expensive. I've blown well over $150 on this little experiment so far.

The boiler is scheduled to be skimmed, but even if it is making some wet steam right now, I thought steam was supposed to snap vents shut?

Brand A: One number four -type seems to work, but it leaks vapor nearly continuously. The other hisses and leaks water vapor like crazy, so I swapped them between two radiators. The hissy one hissed and leaked vapor like crazy on the alternate radiator. Both contained water when I removed them. The fact that one is very hissy and spitty while the other is not suggests a problem with that vent, not wet steam. The steam cannot be all that wet anyway because there is zero water hammer. These both contained water when I removed them.

Brand B: A number four -type, similar to Brand A, works pretty well, except it leaks vapor nearly continuously. This one contained water when I removed it.

Brand C: Within a minute or two the first time the boiler fired up with this one, a little droplet of water jumped onto the mirror. I can hear the vent functioning, but it is nearly always leaking vapor. The vacuum on this one is also very noticeable. I have not removed this one yet to see if it has water inside.

Brand These make a lot of random noises, the vent equivalent of sniffles and coughing. I really don't understand how they function, but ejection of the air seems to also involve ejection of water vapor. These seem to have the least water in them on removal.

Brand E: This one left the radiator stone cold, no matter how I adjusted the dial, apparently an out-of-box failure. At least it does not leak vapor or have water in it on removal.

What am I doing wrong, or is it normal for vents to be leaking some water vapor around 50% of the time?

Jamie Hall

Square one: what pressure is the boiler generating?

gerry gill

boiler piping pictures too please.

Fred

Clearly you didn't get a batch of 5 different brands of vents that were all faulty. Time to look at other system issues, like pressure, which should be no more that 1.5 to 2 PSI Max, Look at if the boiler is piped correctly and why the steam is wet. Vents do close on steam but they don't close on water blowing into them. You said the boiler is scheduled to be skimmed. Oils on the water surface can do a number of strange things. Skim the boiler. Did you put and chemicals/cleaners in the boiler? If so, drain the boiler flush it out and refill it, then skim it. BTW, wet steam likely will not cause hammer. pooling of water in pipes will and more often than not, excessive water in the radiators will cause spitting from the vents. Are the radiators pitched towards the supply pipe? And, if one of your test vents is a Varivalve, pitch it. They almost always spit water.

JUGHNE

Square two: what do you have for main steam pipe vents, in the basement?

307TurboFire

Let me let the contractor get back in here and button this job up.

I am just anxious to do what I can in the meantime. I have been working on this for more than two months now.

I am pretty confident the piping is correct.

Pressure: Vaporstat set under 1PSI cut-out.

Radiator pitch: When I place a four-foot carpenter's level on top of the radiators, taking multiple measurements (along the front, the back, and the middle), the bubble is right at the edge of the marker lines (not level, but not pegged), very slightly sloped toward the supply valve. In my experience repairing fences, bubble snugged up against the edge of one of the marker lines, but not quite pegged, is almost not level to the eye. Or should I just peg the bubble?

The mains may need more venting. This I want to leave to the contractor.

Thanks for your help.

Fred

@307TurboFire , you want at least 1/4" to 1/2" pitch from the vent side of the radiator back to the supply side. Level is not good.