Client called us out today due to hot water tank not working tech went out. Client has a power direct vented hot water tank approximately 12 to 13 years. Old gas valve has failed giving an error code 8 indicating flammable vapour sensors failed tech tried to reset gas valve error code persisted, tech test, tested final vapour sensor, and found that is well within manufactured limits And tried to reset hot water gas valve a second time still error code persisted. Tech made a few options to either replace gas valve or tech recommended replacement of tank. Tech will follow up tomorrow afternoon.