| yes..if you do it right.you have to isolate the zone 1st. There should also be a valve below the spigot..which needs to be closed. The power should be off , so the circulator isnt running . 1st off you need to track where the fresh water is piped into. Older systems and ones installed without the circulator on the supply usually had the fresh water makeup piped to the return somewhere or directly to the top of the boiler( which is ok ) as long as its on the boiler side of the valve below the faucet.
if thats the case then you're gonna have to be careful here not to overfill the boiler..the releif valve will pop allover floor...open the fastfill valve on the water feeder or turn open valve if it has no feeder...fill till boilr pressure is slightly above 25...then with a hose attached and the valve below it closed...open the spigot and let the water flow thru the isolated zone that has the issue....now keep track of the pressure while you're doing this....very important..1..you dont wanna pop the relief...2nd ity wont work so well with no pressure...so it takes a carefull mix of opening the valve and watching the gauge....whats happening here is we are forcing water into the boiler..its gonna flow thru the zone with the hose on it and force out any air in the process.....you can dso this with a cold boiler...but i find it easier when you have hot water in the boiler, then you can actually feel the return pipe gettin hot b/c we forced all the hot water thru the zone and out the "purge valve"...once the return pipe gets hot,,we can assume that the bulk of the air is out. Then shut off spigot, open purge valve and also make sure pressure is back at normal range...then turn boiler on and circulate in that zone to see if return is gettin hot.. | 
Linear Mode
