Navien Tankless Water Heater E760 — Water Leak Detected
Navien Tankless Water Heater · Error code E760
What E760 Means
The internal leak sensor at the base of the unit detected water. The unit shuts down to prevent damage.
Symptoms
- E760 on display
- Water pooling under unit
- Drip visible inside cabinet
- Repeated shutdowns after restart
Common Causes
Pinhole or cracked exchanger — often from freezing or long-term scale corrosion.
Loose union, failed gasket on a port, or weeping pressure relief.
Plugged condensate trap overflowing onto the leak sensor.
External condensation dripping into the cabinet.
Sensor shorted by corrosion.
How to Fix It
- Power off the unit and shut off water supply.
- Open the cabinet and locate the source of water with a flashlight and paper towel.
- If condensate trap is overflowing, clear it (see E193).
- Tighten or reseal any leaking fittings; replace failed O-rings.
- If the heat exchanger itself is leaking, it must be replaced (often a warranty claim — check coverage first).
- Dry the leak sensor and base completely before restoring power.
- If no leak is found and the sensor is wet from condensation, address the moisture source and dry the sensor.
Parts You May Need
If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.
More Navien Tankless Water Heater Codes
Verified against manufacturer documentation: navieninc.com
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.