Taco 400-4 1/8-Inch-NPT Float Air Hy-Vent

These things dont last forever but its working so far. Minerals in the water cause them to leak after a while.

It fit as expected and worked perfectly as part of my preventive maintenance. I could hear the air coming out of the vent after the boiler was filled with water.

I shut the system down, ordered this part, it came in the next day, I installed it. It does what its supposed to, end of story.

Worked well

Works a designed

Feb 2017 update: Its 2017, but I noticed that I havent had a leaking Hy-Vent since I installed a heat pump hot water heater in 2015. This means the hydronic system never fires up to provide domestic hot water during the non-heating seasons. Whereas the oil furnace used to run daily to make hot water for laundry/showers/dishes, now it only runs September to April/May for baseboard heating. I should expect the Hy-Vents to double their service life from 3 years to 6 years. Original review: I would have given it 3.5 stars if possible. It does a great job of purging air from my hydronic/baseboard heating system zones. However, I have been marking dates on them since we remodeled our house 4 years ago, and none of them are older than 3 years. The culprit is always leaking water from the top cap, and I always find that the o-ring has been deformed permanently from just 2-3 years of use (see photos of failed vent valves that Im replacing with new ones I just purchased from Amazon). I would have given it 5 stars if Taco would sell a 3-pack or 5-pack of o-rings for say $2 so I dont have to toss an entire vent when only the o-ring fails. I expect these new ones to not last past 2017. Replacing these vents at the zones is fairly straightforward with only minor water spills and leaks to collect since I have a pair of shutoff valves at each zone. The one on top of the expansion tank is the most challenging since a lot of water comes out of the tank; Im going to use another reviewers advice and install a shutoff valve the next time the expansion tank vent fails.

I installed this at the junction point of the feed manifold from my boiler to all the zones in my house, a direct replacement of a failed automatic bleed valve. This Taco 400-4 works like a charm. Upon refilling of the system, it immediately started hissing, which is good. Overall it took about 20 minutes to purge all the air out of the system. Very impressed. The material, construction and heft of this Taco 400-4 is quite good.

Perfect replacement

Works as expected and price beats local plumbing outlets

Stopped the splashing of hot water through the previous air vent (open pipe) on an atmospheric pressure, gravity fed solar water heating system. Hope it lasts for many years to come.