Bleed Air from boiler system

Obriz

I have a 3 zone Weil McLain HE-II system, that I believe has significant air in it. I get a lot of noise in the pipes while operating.

The problem is I have no bleed valves on my radiators.

I've seen some videos where the air is bleed at the boiler one zone at a time from the spigots there. The problem is all those videos show the spigots on the return side and mine are on the supply side just past the zone valves. Unless I'm looking at it backwards, but I don't think I am.

I have pictures below.

If I open those spigots, isn't the water entering the system from the street just going to go right out before ever going through the pipes?

SeanBeans

I cannot see your photos. I can’t speak for everyone else but I think your photo upload ran into some type of error.

Obriz

Hmm - they display fine for me and I just checked from my phone and I can see them on the post from there too.

Let's see if this works:
https://photos.app.goo.gl/UysRgHaZNCxdaYkL7

https://photos.app.goo.gl/M5qnnYA26TuuMm5g6

STEVEusaPA

If I see it correctly, it looks like you have a boiler drain above each zone valve?
If so, with the system off, close the 3 ball valves below the zone valves (on the supply).
Close the 3 ball valves for each zone on the return.
Put a hose on the hose bib on one boiler drain. I usually put the other end of the hose into a bucket, in a nearby sink. Open the corresponding ball valve to that zone on the return.
Then, at the same time, and keeping the pressure up at 20 psi while doing it, you're going to open the drain valve where the hose is connected, while opening the fast fill to the water feed.
You'll have to find the balance where the pressure stays at around 20psi while filling and purging, watching in the bucket until all air is removed. You can actually kink the hose to control flow.
When that zone is purged, you have to simultaneously close the drain and the fast fill on the water feed.
Then close the ball valve on the return, move the hose to the next zone, and repeat for the last 2 zones. When your on the last zone, bleed off enough water to drop the pressure back to where you want it, around 12psi for a typical 2 story house.
Then open all your ball valves before turning the system back on.
Any residual air should work it's way out of the system thru the proper air elimination components.
I don't see an expansion tank. If it's bladder, that should be isolated and the pressure checked.
If it's a steel tank (non bladder), the valve should be closed during all the purging, then you may need to drain and recharge the tank.

Alan Welch

I would replace the green taco reducing valve first, due to the corrosion.

Obriz

Steve - thanks, that will help a ton.

Alan - thanks - that's on my todo list. It's definitely an issue.

mattmia2

If i'm not mistaken it is pumping toward the expansion tank and boiler and the only air elimination is an automatic vent on the boiler so it isn't going to be super efficient at air elimination.