What actions should I take if my water heater displays 'Error'?

When encountering an error code on the NPE-240A2 front panel, press the Reset button to clear the issue. If it persists or recurs, consult pages 37 and 51 for diagnostic steps and contact a professional installer.

From the official Navien Npe 240a2 manual, page 37

Have a follow-up question?

Answers from the official manual.

Common questions