Rheem tankless water heater displays E76 and will not start

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Incorrect dip switch settings for gas type or altitude, Misconfigured manifold pressure, Wrong model configuration on PCB

Safety first: Turn OFF power and gas.

Locate dip switches: On the main control board, find the bank of dip switches used to set gas type, altitude, and other options.
Check against manual: Compare each switch position to the Rheem installation manual for your exact model, gas type (NG/LP), and installation altitude.
Correct settings: Move switches to the proper positions using a small insulated tool.
Restore power: Turn power back on and test operation. If E76 remains, the control board may be incorrect for the unit or defective.

Medium 3/5

Main Control Board

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