1 inch copper line air

jgaudet

Does anyone know if I am able to bleed this part of my system I included 2 pictures it is a 1 inch copper line that runs from the oil boiler to the wood boiler, I have tried to bleed the zone valves and it seem fine with the oil boiler going but when I light my wood boiler and it takes over and starts it's circulator I hear the air in that 1 inch line

Jamie Hall

Unless there's a bleeder valve on the high points of that line, you really can't bleed it -- what you'll need to do is to get a lot of water going through there somehow and purge it. At a guess, I'd venture you need at least 20 to 30 gpm... but that would do it.

jgaudet

I have a utility pump "pony pump" can I use that somehow to get the water going through it faster? And I have a air separator with a air vent on that line at the high point but it don't seem to take a hole lot of air out I circled where the separator is

hot_rod

It might be good to have an air separator at each boiler, as close to the hottest piping, the boiler supply typically.

jgaudet

Ok well I got heat for now and I'm doing a major overhaul in the spring to the system so I might just leave it for now means I have heat and when I do the overhaul I'll put a separator on the supply side of each boiler!  I just figured there might be a quick way I could purge air out of that line that I didn't know of lol

Jamie Hall

Getting the air out of that line can be done... eventually... someday... with the air separators. ;;To really get it out, though, you have to get the velocity up -- just like purging any other hot water or radiant floor loop. Is there any way you can isolate that loop and pump a lot of water all the way through it? Then open the isolating valves so you don't get more air in?

One other thought does occur -- what is the static pressure in that system? I assume that it's high enough to make sure that the top of the loop is never at less than 5 psi or so, but... if that loop is actually below atmospheric pressure, then you are going to NOT want air separators on it, as they let air in too.

hot_rod

Microbubbles form every time a boiler heats up. If not completely removed they go back into solution when the water cools, the cycle repeats.
Common ramp scoops cannot, will not remove microbubbles. An auto vent on top of a large chamber boiler actually does a better job with micro bubble removal. Design engineers understand this which is why the microbubble resorbers were developed. They are crucial on todays low volume thin metal heat exchangers as those bubbles clinging onto the boiler metal can cause hot spots and rapid failures.

Not a sales pitch, I have watched these devices perform in actual and lab conditions, no denying physics and what you can measure and observe.

A @Jamie Hall mentioned, velocity, around 8 gpm in that 1" section will help. And increasing fill pressures reduces large bubbles to help them flow to any removal device.

Bite the bullet and add microbubble air purgers at both boilers when you do a remodel. Your life will be forever changed.

jgaudet

@Jamie Hall I don't think I can isolate that part! And my psi in the system stays around 15psi, on my circulator I have 3 speeds I use number 1 what if I was to use number 3 speed to get it going faster?  

@hot_rod that is my plan I think I will be purchasing a couple of caleffis to put in the system when I do my remodel!

Jamie Hall

The higher speed won't hurt a bit -- assuming it works OK with the rest of the setup.

jgaudet

I just set the speed at medium for now I'll run it a few days on medium and if it seems like the air is mostly out I'll put it back on low setting, all my rads get hot on the low and my circulator is really quiet on that setting