Your friend is correct

Baseboard systems are bled at the furnace. They have no traditional bleed valves.

If properly designed, the feed water regulation valve (which normally limits the pressure to 12 psi) has a bypass arm that allows unlimited pressure to the system. This must be used carefully and with the full understanding that you cannot exceed 30 psi without blowing the pressure relief valve.

The return line to the circulator will have a shutoff valve to prevent flow into the furnace.

Directly above the shutoff valve will be another shutoff valve with a spigot to allow a connection to a garden hose.

The system is bled as follows:

1) Ensure the valve for the zone you want to bleed is open. Manually move the arm on the side of the zone valve to lock it in the open position. (Do not turn up the thermostat).

2) Connect a garden hose to the spigot and run it outside.

3) Shutoff the valve directly above the circulator (and below the valve at the spigot)

3) Slide the bypass arm on the pressure regulating valve to allow unlimited pressure to the furnace.

4) WATCH THE PRESSURE GAUGE while keeping one hand on the valve handle at the spigot.

5) Open the valve at the spigot and keep the pressure between 20-25 lb.

6) "Shock" the system many times by quickly closing and fully opening the valve. The pressure will climb toward 30 psi and then fall (when the valve is fully opened) during the process..............not a problem............keep it between 17 and 27 psi.............don't approach 30 psi.

7) You can hear the air in the lines and, when the bleeding is complete, the noise from the air will stop (typically about five minutes).

8) Slide the bypass arm back to the fully regulated position.

9) Wait for the pressure to fall back to 12 psi and close the valve at the spigot.

10) Open the valve directly above the circulator.

11) Move the locking arm on the zone valve back to the normal operating position.

12) Repeat the above for each zone in the house.