Circulator pump Here to replace 2nd floor bedroom circulator pump. Boiler expansion tank and relief valve. Dropped boiler water pressure to begin process of remove and replacing male relief valve @ boiler. Un-screw fittings and remove old existing relief. Teflon and dope new relief valve before securing tightly. Connected fitting back to relief valve. Isolate expansion tank and circulation pump. Disconnect electrical connection @ pump, remove bolts to separate circulator pump from zone piping. Installed new circulator pump connected electrical wiring. Unmount expansion tank. Teflon and dope new expansion tank and secure tightly. Open all isolation valve @ boiler to run and test boiler operation. Needed to purge 2nd floor bedroom zone. Checked that all zone are free of air from purging of zones. Checked flow @ supply and return pipes. Checked temperature spilt @ bedroom outlets. Second floor system is back up for normal operation. Ran and tested all zones a boiler. Boiler is back to n