[jsb5717]

On our older 5ers I discovered by accident that the connectors to the main board don’t always make good contact. Sometimes just jiggling the connectors a bit can regain function. This has helped on 3 different RV to get the furnace to work. Might work on the water heater as well since the boards are often basically the same. Also, it could simply be the main board as well as any of the items listed above.