What does error code E762 mean on a Navien tankless water heater?

Vent pipe not properly inserted. The vent pipe isn't properly inserted.

When should I call a technician for code E762?

Venting problems can let exhaust into the home. Have a qualified technician fix it before using the heater. If anyone feels dizzy or a CO alarm sounds, get outside and call 911. Smell gas? Leave right away, don't touch light switches or phones inside, and call your gas utility or 911 from outside. Never open a gas valve, burner, gas line, vent or flue connection, or bypass a safety switch. Repeated lockouts, scorching, soot, or a CO alarm mean shut it off and call a licensed gas technician.

Navien Tankless Water Heater Error Code E762: Vent pipe not…

What E762 means

The vent pipe isn't properly inserted.

Likely causes

Vent pipe loose or disconnected

Safe first checks

Turn the heater off.

When to stop

Venting problems can let exhaust into the home. Have a qualified technician fix it before using the heater. If anyone feels dizzy or a CO alarm sounds, get outside and call 911.

Checked against: Navien NPE-2 user's information manual: understanding error codes. Codes can differ by model and year, so confirm with your owner's manual.