Heating Help

Mono flo system one zone how to bleed valves on multiple stories ?

I have a 2 family house with a 1 zone monoflo system built in 1955

There are 3 rads in the basement and a 1st floor 3bdrm  apartment and a 2nd floor 3 bdrm apartment. I had a friend repair a valve and a minor leak at a T section.

What is the best way to bleed the air out of the system?

1) raise the themostat
2) Bleed each rad starting ...basement 1st floor second floor?

The thermostat..

is not going to help you. Your friend should have bled the heat if he was capable of doing the repair.
Each radiator has a vent that will have to be opened to remove the air. Provided the water feed to the boiler works properly that will do it.

bleed mono flow zone

Open top radiator air vent, turn on water at boiler and watch vent . As water fills it should spit out the vent. Do this until air stops and you get full stream of water. Now turn up thermostat and see if heat will come to each radiator. You will probably have to vent each radiator if they heat up.