Return to make repairs on Crown gas water boiler ( expansion tank / air vent / boiler drain ) - shut power to boiler - Shut water feed to boiler - Close all supply and return ball valves - Drain down boiler - Removed the existing expansion tank, air vent and boiler drain - Pipe in and install brand new expansion tank, air vent and boiler drain and secure all connections - When installing the expansion tank, extend 1/2 piping and install elbow to drop tank from sideways to hanging - Support pipe with threaded rod, split rings hanger and base plate - Open water feed back to boiler and fill system and purge all air from boiler - Return power to system - Start with opening basement supply and return and call for heating at thermostat - boiler fires and circulator pump is on and running- monitor system operations, boiler pressure and temperature and confirm system satisfied at temp of 180 and supply / baseboard and return piping are all heating properly - Open all supply and return valv