Rheem RTGH-RH10DV Service Manual page 76

76
Error
Connection error between control panel and circuit board.
① Check connections from circuit board to Control Panel.
② To reset this error code, the power needs to be disconnected and then reconnected.
Meaning
Communication Error between
Control Panel and Circuit Board
(Automatic restore)
Fault
Check point
Chapter 4 Troubleshooting
Condition
When communication with display
panel is not stabilished for 10 minutes,
error code 76 will appear.