Current Favorite Auto Air Valve?

NEMatt · January 2025

Just had to replace the expansion tank and relief on my 15yo EK1 boiler that failed this past Monday. It seems the relief valve stuck, pressurized beyond 30, and then blew off with enough force to slam the spring up and cam the relief valve lever over into the Open position, where it stayed. Pretty wild. That also meant it drained a fair bit of the system by the time I ran downstairs and turned stuff off.

Anyway, replaced the relief valve and tank and had my local guy refill/purge. However I am now trying to get remaining entrained air out of the system.

3 Zones, and the plumbing contractor in the 70s only saw fit to add manual bleeders on like 10% of radiators 🙄.

I have a feeling the two old Caleffi air valves that came plumbed with the EK1 from the factory are beyond their service life and aren't helping my cause. One is quite crusty indeed, the other sorta spits both air and water.

What are y'all's favorite valves currently? Any purpose in putting a Spirovent or similar in place of the originals?

Thanks

hot_rod · January 2025

If you have a Caleffi, 5020, 21, 22 or 23 you can buy a top rebuild kit. The brass doesn't wear out.

It is dirt, debris, silica, teflon tape, rust solder flux, etc in your system that gets into the needle valve that causes a seep or drip. If you take the top off you can clean that with a Q tip.

The Caleffi should maintain a small air space on top of the water level inside. This helps keep dirt out of the needle valve. So don't push down the air release and vent out that small bubble of air. See the blue and white in the cutaway view.

Regardless of what brand you use, they all need maintenance on systems with dirty water.

You can add a hydroscopic cap to the Caleffi also, as a second shut off if the valve inside fails.

Air hissing or spitting is an indication that it is doing it's job,

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mattmia2 · January 2025

A microbubble separator can help but if there is a vent tapping in the boiler hx itself I'm not sure the microbubble separator is going to do anything that the water slowing down in the boiler and being heated isn't.

NEMatt · January 2025

@hot_rod based on photos I believe both vents are 5026 with the black plastic caps.

SuperTech · January 2025

I work on a lot of EK-1 boilers and I prefer to use the Caleffi automatic air vents on them. You will probably need a 3/4" or 1/2" air vent depending on when your boiler was made. The Energy Kinetics dynamic air separator on the boiler is all you need. I don't think you have anything to gain by installing a Spirovent or something like that.