What does error code E515 mean on a Navien tankless water heater?

PCB fault. Abnormal operation of the main circuit board.

Can I fix Navien code E515 myself?

Start with these safe checks: Make sure the power cord is properly grounded. If it continues, contact Navien technical support.

When should I call a technician for code E515?

If it continues, contact Navien technical support. 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

Navien tankless water heater code E515: PCB fault

Navien NPE-2 tankless water heaters

What E515 means

Abnormal operation of the main circuit board.

Likely causes

Poor grounding
Board fault

Safe first checks

Make sure the power cord is properly grounded.

When to stop

If it continues, contact Navien technical support.

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.