Hi. My mom has a rough old house, and she didn't have enough heat on the first floor, so I added 3 new radiators by running 3/4 pex on the ceiling. Now the problem is I realized there is probably a lot of air in that pex up high, since it keeps coming down to the rad and then back up and down to the next one.

Should I add two boiler drains to the loop in the cellar and try and blow the air out?

Or maybe just one boiler drain and try and use the bleeder valves on the rads to let air/water out?

Or just let the air sit and keep using only the bleeder valves on the rads?

Thanks!

DD