On the covered Navien tankless water heater, E782 means abnormal main-panel communication. First, turn the heater off and on once at the front panel. Then: Navien's action: check the PCB. Navien says the reset for its error codes is to press the Reset button on the front panel, or to disconnect and reconnect electrical power to the heater.
Try in this order
0 of 3 completedWhat to do first
ReversibleTurn the heater off and on once at the front panel.
Correct only the documented fault domain
ReversibleNavien's action: check the PCB. Navien says the reset for its error codes is to press the Reset button on the front panel, or to disconnect and reconnect electrical power to the heater.
Book a licensed technician
ReversibleE782 is a communication error inside the main panel, an electrical fault that calls for inspecting the circuit board and replacing it if needed.
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Common questions about “Navien tankless water heater code E782”
What does E782 mean on a Navien tankless water heater?+
Abnormal main-panel communication.
Can I reset a Navien E782?+
A power reset is harmless to try, but the fault sits in the electronics of the main panel, so a licensed technician should check the circuit board.