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

Needed replacement for a 1962 boiler. works fine venting the system.

This valve was an exact replacement for our old, rusted, leaking one. Installation was not too tough, but be prepared for some squirting water! It works perfectly now.

Easy installation

Same model number as the one my heating contractor had previously used on my system, but they wanted $160 to replace this and a Caleffi auto air vent. This Taco automatic air vent was very easy to replace. Shut off the water supply, close the existing ball valves to isolate the boiler or zone, drain the boiler until the pressure gauge drops to zero. Unscrew the old valve, put Teflon tape on the new one and screw on the new valve. Reverse the process and youre done in 10 minutes. Remember to keep the metal cap loosely in place to allow the air to escape. Note that if you have a tight clearance issue, the Caleffi automatic air vent has a 1/8 narrower profile, which is why the pros had used two different brands on my system (a riser comes very close to the air vent on top of my boiler and the Taco wouldnt fit). Other than where there are clearance issues, my heating contractor prefers Taco.

Yup works just like the last one I changed

From the time I installed this on a water softener system it constantly sticks. If I forget to go into the pump room and tap it every few days I get air in the water lines. It works fine once I tap on it but it doesnt want to open on its own. Its almost the exact same design as the one it replaced, and the old one never had a problem until the plastic parts just got brittle from age and broke. I suspect most designs are similar but Im trying another brand.

Connected to my solar hot water system. Heard air exiting until the system reached 10 psi. Well made product.

Package was beat up. Product survived, though.

Works great. Was very easy to install. I recommend this product. I might Buy an extra one to have in case I need it but this one seems very solid.

I ordered this air vent to replace our old Maid-O-Mist vent, which has started to leak water and was heavily covered by mineral deposits. The product arrived exactly as shown on photo, its build quality is excellent, well worth its price and should last many, many more years.