Navien Error Code E001: Ignition Failure

How to Fix Navien Code E001

1. Step 1: Locate your gas shutoff valve (typically a yellow lever or valve on the gas line near the unit). Ensure it is fully turned to the 'on' position (parallel to pipe). Do not touch any internal parts.
2. Step 2: Press and hold the red or black reset button for 3 seconds, then release. Wait for the unit to attempt a restart. If it clears and runs, you're fine for now.
3. Step 3: If the code returns, or if you smell gas at any point, turn the gas off at the valve, open windows, and call a licensed HVAC pro. Do not attempt to clean the flame sensor or burner yourself.

How to Reset Navien Code E001

1. Turn off the unit using the power button on the front panel.
2. Turn off the gas supply valve.
3. Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
4. Restore power at the breaker, then open the gas valve.
5. Turn the unit back on. If the error returns, the underlying issue needs repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Navien Error Code E001 Mean?

Error code E001 on a Navien unit means the ignition control module tried to light the burner but didn't detect a flame within the safety timing window (typically 10-15 seconds). This is the most common lockout on Navien condensing boilers and water heaters, especially in the NCB, NPE, and NHB series. The system will attempt up to five retries before locking out permanently with this code. The most frequent causes are a blocked flame sensor (a metal rod inside the burner that reads flame current), a fouled burner (from dust or soot), or a failed hot surface igniter (HSI) on newer models. Older NPE models use a spark igniter, so the root cause differs by series. The control board monitors flame current in microamps (µA); if it drops below 0.5 µA after ignition, it shuts the gas valve and logs E001. Sometimes the issue is simpler: a gas supply problem like a closed shutoff valve, low gas pressure (under 7 inches water column for natural gas), or air in the gas line after a new installation. Navien's multifunction valve (gas valve) includes the regulator, so a bad valve diaphragm can also cause this code—especially on units over 5 years old.

Common Causes

• Dirty flame sensor rod—coated with carbon or soot from normal combustion over time.
• Fouled burner or blocked air intake—dust, lint, or debris reducing proper flame formation.
• Gas supply issue—shutoff valve partially closed, low gas pressure (under 7 in WC), or air in gas line.
• Failed igniter—hot surface igniter cracked or burned out (gas models) or spark igniter/wiring fault (NPE series).

Diagnostic Steps

Recall Notices

Replacement Parts

Related Codes on Same Models

Other codes that affect the same Navien model families as E001.