Watts 0590715 1/8" FV-4M1 Automatic Float Vent

Exactly what they are described as

Before I bought this, I could not get the air out of my hydronic baseboard system. I would hear gurggling when the heat ran and it ran for long periods of time with the baseboard units not getting very hot. Added this air vent and immediately heard it venting the air until the pipes filled with water. Just turn the top know open 2 turns. Also, needed to empty the system of water for a repair and the unit acts as a vacuum breaker allowing air to enter the system when water is not at the valve. Best part is it’s a solid piece of plumbing and it’s small enough to fit inside my baseboard covers.

I did not install it yet, but it is the identical vent that has been on my boiler for many, many years, which I just found out that the threads on the plastic manual bleed at the top have stripped. The old valve is still fine, and I could just put the plastic screw from tis on onto the old unit, but for good measure, I will replace the unit. Having had the old unit on my boiler for so many reliable years, and this one being of identical construction by the same manufacturer, I give this a 5 star rating from experience.

I saw a couple of reviews that folks were using this to vent their pool pumps. I installed it in line with my pool pressure gauge and it works great. When I turn on the pump it hisses out the air and then shuts off automatically. I left the manual air release in place too, in case I need it. I double checked and there was no air left in the filter vessel. So much more convenient than a manual release and WAY cheaper than the plastomatic ARV valves we use at work ($300+), for the price of one of those I can buy 20 of these!

Unable to open for cleaning and non existent customer support from Watts.

Old valve was full of sediment. This was a direct replacement and works as specified.

This is the third float vent of this model on my hot water boiler. The first one lasted about 10 years before failing. The second one about 5 years. Last winter we had air in the system with pounding when zones shut off. I did not want to mess with it during the heating season. Replaced it this summer and bled the system manually. Have had a few nights with heat and all quiet so far. I am sticking with this same model because they are relatively inexpensive and pretty easy to replace. I'll order a spare to keep on hand.

I put this on my highest elevation radiator. It didn't solve my problem(gurgling when the pump ran). My real problem was the water intake pipe, which was clogged with rust. I fixed that and had to refill the system. As it was filling the auto vent hissed nicely as it bled off the air in the system. A few more burps when the pump came on. Now the system runs perfectly quiet and I didn't have to manually bleed the system. As a side note, I believe the plastic screw on top has two positions: Loose is for auto vent, tight is for when it starts leaking with age or to prevent the possibility of leaking when you don't need it to vent. I have a single loop system so one of these is probably enough. If you have multiple zones you might want one between the boiler and the pump and possibly one in each zone on a radiator. Anyway, I am very happy with this product. It makes dealing with a hydronic system much easier. Be aware that as these age they may leak and cause water damage in your house. This is a good web site for hydronic system maintenance: http://www.ronstultz.com/knowledge/Documents/Hydronic%20Heating%20System/Hydronic%20Heating%20System%20-%20All%20Things%20Related.htm