Need Help Purging Air from Hydronic Oil Heating System

Straightahead

I'm changing a section of baseboard in a bathroom in my house. I will need to bleed the air out of the system after installing the new section and have a beginner understanding of the procedure.

My first issue is that I can't find the shutoff to close before draining the loop. I'm enclosing a photo of a drain valve on one of the upstairs loops. It seems to have what might be a small shutoff valve right next to the drain valve, but I was thinking the shutoff should be more substantial than this one.

Can you confirm if it is the shutoff or is it a balancing device or something else?

Sorry if I'm using the wrong terminology or if I'm way off base in my thinking.

I've also identified 2 loops for my upstairs where the bathroom is. I'm assuming that I should bleed both of these loops, but could use some advice.

If this isn't the shutoff, I can send other photos, as needed, to help me find it.

Help would be appreciated. Thanks

hot_rod

Looks like a butterfly type shut off and purge cock. Does it move about 1/4 turn?

pedmec

when i got in the trade we called it a balance and purge valve. good luck turning that closed. its looks like you might get lucky as the stem looks thicker than the ones i have dealt with and the whole valve looks cleaner. The ones around my location always had like a pin for a stem and use to snap when trying to close.

Straightahead

So, if there are two upstairs loops, do i need to purge them both? FYI, they are using the same zone valve if that makes a difference.

Thanks

hot_rod

the highest zones, loops, piping are typically where air ends up. Do every piece of piping needs to be purged.