Navien E760: flushing and service alarm

E760 is Navien's way of saying it is time for maintenance. Condensing tankless heaters need regular flushing to remove scale, especially with hard water.

The meaning and recommended action below come from Navien's User's Information Manual for NPE-2 condensing water heaters (NPE-180A2, NPE-210A2, NPE-240A2 and the S2 models). Navien technical support: 1-800-519-8794.

What routine service includes

1. Flushing the heat exchanger. Navien's procedure circulates a diluted cleaning solution through the heater with a pump for at least 45 minutes, then rinses it.
2. Cleaning the cold water inlet filter and, on A2 models, the recirculation inlet filter.
3. Cleaning the air intake filter. Navien recommends this every 3 to 4 months.

Our guides to descale a tankless water heater and Navien tankless water heater maintenance cover the steps in more detail.

Why not ignore it

Scale makes the heat exchanger run hot and can lead to overheating codes such as E016 and E030. Navien's warranty excludes damage from hard water deposits and lime buildup, so keep a record of each service.

Before you call

Have the model number and serial number from the rating plate on the side of the unit ready, along with the date it was installed and the exact code. Navien asks for this information when you contact technical support, and your installer should be your first call for warranty service.

See every code on our Navien error codes page.