I have a Hot Water zoned heating system. All zones are flowing except one. The zone not circulating has a lot of air in it and it appears to have an air lock. I have bled the baseboard radiators but can not seem to get the air lock out - it will not move. What can I do to get this circulating properly... Can I drain the zone and see if it will fill up again or is there an easier way?

Depending upon your setup you could try to boost the water pressure in the system past the 12 pound normal setting to 20 or so but not past 25 since the pop off/safety usually will let go at 30. This will force more water into the system to increase pressure and hopefully expel the air trapped inside. Try to make sure that the other zones are off and the only one circulating is the trouble zone.You may end up having to call for a on site pro if the problem persists.
Remember to return the system to the normal operating pressure whatever that was.