Navien Error Code E010 — What It Means
Navien error code E010 indicates an air pressure sensor (APS) fault. The APS is a differential pressure sensor that monitors the draft produced by the combustion blower to verify adequate airflow before and during combustion. If the measured pressure differential is outside the expected range — either too low (insufficient draft) or reading zero when the fan is running — the unit faults on E010 and shuts down. This fault prevents the unit from firing without proper combustion air, protecting against combustion gas spillage. E010 is common in winter when intake or exhaust vent terminations become blocked.
Common Causes
- Blocked combustion air intake or exhaust vent — Ice buildup, bird nests, or debris on the PVC vent terminations at the exterior wall block airflow. The APS detects low pressure differential and faults.
- Disconnected or cracked APS hose — The small rubber tubing connecting the APS to the combustion blower housing can crack, slip off, or become blocked with condensate, causing the pressure reading to be wrong.
- Failed APS (pressure sensor) — The differential pressure transducer inside the sensor fails and reports an out-of-range voltage regardless of actual blower operation.
- Combustion blower failure — If the blower motor is failing or not reaching operating speed, it won’t generate the required pressure differential and E010 follows.
Step-by-Step Fix {#fix}
- Check both vent terminations — Go outside and inspect both the intake and exhaust PVC pipes. Clear any ice, debris, or animal nesting. On vertical-discharge units, check for ice dams at the pipe end. Vent terminations must be open and unobstructed.
- Inspect the APS tubing — Locate the APS inside the unit (typically mounted near the blower). Trace both rubber hose connections from the APS to the blower housing. Confirm both are fully seated and not cracked. Blow through each hose to check for blockage.
- Test the combustion blower — With the unit calling for heat, the blower should ramp up immediately. Listen for bearing noise, sluggish startup, or intermittent operation. Measure amp draw if possible.
- Test the APS directly — Connect a digital manometer or water column gauge to the APS ports and measure pressure with the blower running. Compare against the APS specification in the Navien service manual.
- Replace the APS if confirmed failed — Remove the two hose connections, unplug the electrical connector, and unscrew the APS. Install the replacement and verify hose routing before restoring power.
Parts Often Needed
| Part | Notes |
|---|---|
| Air pressure sensor (APS) | Amazon | Navien part; match to unit model — setpoints differ by BTU rating |
| APS tubing (replacement) | Amazon | Cheap; replace if cracked or contaminated |
| Combustion blower assembly | Amazon | Replace if blower speed is confirmed low under load |
When to Call a Pro
If the vent terminations are clear, the APS hoses are intact, and the blower is running at full speed but E010 persists, the APS calibration or the blower’s actual pressure output requires measurement. This requires a manometer and familiarity with Navien’s pressure specifications.