Help Lorenzo install water heater Here to install 75 Gallon AO smith HWH Drain old existing HWH- Cut copper piping Disconnect gas line and remove to take out existing HWH Disconnect Flue/smoke pipe Remove old existing 75Gal AO Smith HWH Remove existing expansion tank and mixing valve. Installed new 75 Gallon AO Smith HWH Re-Connect copper piping hot, cold and mix Installed new expansion tank and mixing valve. Reconnect gas line. Check for leak w/ gas leak solution. No leak. Purge gas line. Installed flue/ smoke pipe Fire up HWH and set mixing valve to customer desire temperature. Purge all faucet hot and cold to remove air from all lines. Ran and monitor HWH all good View visual findings from this job here - https://visionshare.xoi.io/?id=XA-57DC-89F8E06E3D1C4772A457F67C918DB6B1