How to drain a boiler

[velvetfoot]

Maybe this valve on top bleeds air out?

Yes it does. That's an air separator it sits on.

 

[cableman]

So once i drain boiler below what i need to change, i just turn feed back on fill and most of the air should bleed out w/o effecting zones?

 

[Dougsey]

My guess is you're going to have to purge your zones to get all the air out.

 

[velvetfoot]

So once i drain boiler below what i need to change, i just turn feed back on fill and most of the air should bleed out w/o effecting zones?

I would say so. The air separator should take care of what's left once things are hot and moving...in theory, lol. I replaced my cast iron air separator with a Spirovent, but there are probably millions of the ci type installed, so they must be doing some good!

 

[cableman]

I would say so. The air separator should take care of what's left once things are hot and moving...in theory, lol. I replaced my cast iron air separator with a Spirovent, but there are probably millions of the ci type installed, so they must be doing some good!

With this spirovent thing, would that replace that green piece on mine that my seperatpr is screwed into?

 

[velvetfoot]

Yes. They are called air separators. When the water gets hot there's a tendency for air to undissolve and the air separators collect this and then vent it out. The vent that screws into the green piece is just a vent-it lets air out but not water.

 

[cableman]

I asked some aquastat questions on heating help and got one response, seems like my air seperator is not in a good spot to work correctly and my fill line is on the return line but should be on feed side. This stuff gets confusing!
Ill prolly leave it as is keeping boiler warm at 120 with dif on aquastat set at 10 or 15 for the heating season, then shut er down for non heating season.