Best air extraction for hydronic heat?

[jadnashua]

The piping for my heating system is fairly complex: primary/secondary loops off the boiler for the hydro-air and radiant floor heating circuits, priority circuit for the indirect, 4 circulators (primary loop, indirect, hydro-air, radiant floor), etc. They installed a Spirovent in the secondary loop, but it is at the lowest point in the system. I have been getting some air in the system. No obvious leaks.

Do you think that adding a second Spirovent (any recommendattions for other brands?) at a higher point would aid things?

Any suggestions on finding an air leak that isn't weeping any water? The pex manifolds and the hydro-air units are readily accessible as are the pumps and controllers.

[jadnashua]

Any thoughts or suggestions?

[seaneys]

I installed a spirovent a few weeks ago. I'm positive the mfg recommends placing them at a high point in the system.

I actually did a spirovent along a high point of the main line and a bleed valve next to the auxiliary accumulator off of the boiler..

Steve

[poorplmbr]

The installation should have had an air eliminator at the top op the systen at the hydro-coils........I like to use these....

The Spirotop® Air Release Valve is essentially the vent head used on all products through 12”. It has a ½” bottom connection and can be used in places where other float vents have been used. Carries a 20 year Limited Warranty and is designed not to leak by means of a dry air chamber

http://www.terrylove.com/forums/attachment.php?attachmentid=3448&stc=1&d=1199026452

[hj]

The most common place for air to enter a system is at the pump's shaft seal. Everywhere else the system is at a postive pressure so the water would leak out, but air could not leak in. If the air is caused by fresh water replacement, then closing the water feed valve would quickly show if there is water leaking from the system.

[Bill Arden]

My dad had some problems getting the air out.

He had several places where the pipe size was too large to pull bubbles down when the pump was running and you could hear the pipes gurgle.

I recommended he add two T's and two small manual valves for bucket bleeding.

Instead he had a local Hvac guy come out and the guy used a pump to suck all the water/antifreeze out into 5 gallon buckets.

The Hvac guy then used his pump to pump the same water/antifreeze back in again and pressurize the system. (the system uses an expansion tank)

It worked, but I am guessing that the manual purge valves would also have worked.

FYI: I've seen the "automatic" purge valves start to leak when they get gummed up by the antifreeze.

[seaneys]

The most common place for air to enter a system is at the pump's shaft seal. Everywhere else the system is at a postive pressure so the water would leak out, but air could not leak in. If the air is caused by fresh water replacement, then closing the water feed valve would quickly show if there is water leaking from the system.

How long has the system been closed? Could the air have been trapped and is simply slowly coming out.

I've added several air eliminators around my system for good measure.

Unless I am mistaken, doesn't a Spirovent require flow, where an air eliminator wants to burp the air out of a high point?

Steve

[jadnashua]

A Spirovent literally combs microbubbles out of the water stream...it needs flow across it to work. The instructions say to put in on the hottest portion on the suction side of the pump. That's where mine is, but, all of the pipes come out of the bottom of the boiler, then go up. I'm guessing that any trapped air is also going up, although some would get absorbed in the water stream along the way. Not sure what I'll do, I can manually bleed it when needed, but that's a pain.