Maid-O'-MistMaid O' Mist No. 67 Auto-Vent

Exact fit

did job very well. a few zones on our boiler system were not getting the hot water pumped through it. the furnace had a gauge which read about 8 p.s.i. which said to me the plumbing runs at that pressure. I read you have to match the expansion tank to whatever pressure you are running. after shutting off the pumps and draining the water from the boiler plumbing then checking pressure to the expansion tank it read nothing. I filled first with 12 psi for a week or so because I read online that was standard. I let it run a week and no improvement on the circulation to the two zones. I opened up the very top of our old maid-o mist air vent and pushed down on the valve and it began leaking water. so it dripped and leaked slowly until ordering this replacement same exact part but a new one. When I got it I did the same thing turned off pums drained all water from the lowest point of the boiler system with a garden hose pumping out all the hot water outside, then took channel locks and squeezed the middle of the old maid o mist no 67 auto vent crushing it then turning it and got it out. put the new one in per instructions on box. when on box it said loosen it slightly they mean the very top cap and I saw why when it began working a bit later. Next I reduced the air pressure by pushing the needle of the shrader at the bottom of the expansion tank to 8 psi matching our house (boiler system) pressure. with the new no 67 auto vent installed I closed the drain valve disconnected garden hose, turned back on the pumps and valves to incoming hot waters and within a minute I began hearing this thing working to neutralize air pressure. we had to turn off a few zone valves to have hot water again for some reason because we had also just replaced one of our pumps but it was a smaller pump than we should have. once this worked, we were able to get hot water on every zone including the apprx. 500 ft of radiant floor heating zone that I had installed last fall to heat the kitchen, family room, and two other rooms. now all has been good. this little guy did quite a bit for the 7 bux and now nothing is leaking where the boiler is. We have an outdoor wood boiler that we use to heat house and hot water during the cold months and switch to propane to just heat the hot water when its warm outside. I do plan to next cut out a section of our copper pipe during the off season which is all corroded and has a lot of white scale all around it because i fear its pinching our water pressure from the inside thus reducing our flow and pressure. but all has been good since. incredibly pleased with this little piece. I noticed its popular this vent no. 67 although its available in other numbers this one also exists on my grandmothers brand new furnace she just got set up this yr by the professionals at wesco when she switched propane because they gave her half the price of the other company she had for propane, they found severe problems with her old one. this no. 67 auto vent I noticed also exists on her setup.

Worked well to replace identical valve

This is the perfect air vent for a chlorinator

First valve delivered was used. Replacement was ok but not clean looking like picture Also picture shows the box ,valve and shut off fitting.You get the box and valve. Fitting has to be ordered separately. Fooled me.Why show something that's not included. Read description carefully