What you'll notice with E351
- Recirculation stops working; long waits for hot water
- Temperature at the far fixture swings
- Code appears mainly on NPE-A2 units with built-in recirculation
Navien E351 Error Code: Recirculation Sensor Fault
Water-related sensor fault on the recirculation/return side.
Service soon
Open 24/7 · CSLB #1008381 · Joseph J. Castro, Owner
Quick answer
Navien E351 means: Water-related sensor fault on the recirculation/return side. It's usually caused by failed or shorted temperature sensor, damaged harness, or scale on the sensor probe. The fix: Ohm-test the sensor, inspect wiring, descale or replace the sensor, then verify recirculation temperatures. Efficient Water Heaters, Inc. diagnoses Navien E351 faults across San Jose 24 hours a day, 7 days a week — (408) 470-0191, CSLB #1008381.
What causes it
Failed or shorted temperature sensor, damaged harness, or scale on the sensor probe.
Safe steps you can take right now
- 1Note whether hot water still works normally when you run a tap directly — usually it does.
- 2Check your NaviLink recirculation schedule in case it was changed.
- 3Schedule service; this rarely resolves itself.
How we fix E351
We ohm-test the return-side sensor against Navien's resistance table, inspect the harness and connector for corrosion, and descale a scaled probe. Then we verify recirculation temperatures through a full cycle.
Ohm-test the sensor, inspect wiring, descale or replace the sensor, then verify recirculation temperatures.
Get your Navien E351 fixed
Call (408) 470-0191 any hour, or send the form and we'll reach out.
Navien E351 — related services, cities, and codes
E351 rarely shows up alone. These are the services that resolve it, the cities we cover, and the codes that often appear alongside it.