Recently my hot water heating system has been ‘banging the baseboards’….most likely there is air in the system..Id like to know the best way to properly bleed the ‘system;..I have periodically pushed in the tiny air valve..air is released then it is followed by water..However this doesnt seem to correct the problem…Should I open the relef valve and see what happens??? iv never worked on a system like this before?? Any suggestions/help is most appreciative ..Thanks DZ