View visual findings from this job here - https://visionshare.xoi.io/?id=XA-90AE-C5F247EE2A2246BBBBEB63921CE05F64 Return to replace (3) way valve inside Navien combi gas water boiler: * shut power down to system * isolate all heating zones on supply and returns * close water feed to boiler * close cold water supply for hot water * close all valve under boiler * drain down boiler removing all water * disconnected electrical from 3 way valve * removed bad 3 way valve from boiler * install and secure brand new three way valve and O rings inside boiler * install and secure electrical back to new three way valve * reassembled boiler and all components * while boiler is drained clean both DHW and CH screens and reinstalled * open cold water supply back to boiler for DHW and flush out hot side - open all valves back for DHW * open supply and return piping under boiler drain down and open water feed back to system * check for leaks- none * return power back to boiler * place boiler into air