Navien E010 Error Code — What It Means
The E010 error code on a Navien tankless water heater indicates an abnormal air pressure or airflow fault in the combustion system. This is not a water flow or ignition problem. The fault typically stems from restricted airflow in the intake or exhaust venting, a clogged air filter, or a blockage in the condensate drain path that interferes with the air pressure sensor circuit.
The heater’s air pressure sensor monitors combustion air supply and exhaust conditions. When it detects abnormal pressure, it shuts down the burner and logs E010. The most common real-world fixes involve clearing obstructions in the venting system or cleaning the air filter, which restores normal airflow and clears the code.
Common Causes
- Blocked or improperly installed intake or exhaust venting Obstructions, crushed pipe, improper termination, or vent installation errors restrict airflow and trigger the air pressure fault.
- Dirty or clogged air filter A restricted air filter limits combustion air supply and is one of the most common field causes of E010.
- Condensate trap or drain blockage Blockage in the condensate path can interfere with airflow or pressure sensing and cause the error.
- Faulty air pressure sensor or disconnected tubing A defective sensor, damaged tubing, or loose hose connection can produce false pressure readings even when vents and filters are clean.
- Combustion air supply problems from installation environment Inadequate combustion air or vent termination issues in the mechanical room can create abnormal pressure conditions.
Step-by-Step Fix
- Reset the unit and observe whether the error returns immediately or intermittently to determine if the fault is persistent or transient.
- Inspect the intake and exhaust venting system for obstructions, crushed or kinked pipe, improper termination, bird nests, or ice buildup at the vent terminus.
- Remove and clean the air filter on the unit, as a clogged filter is the most common fix for E010 in the field.
- Check the condensate trap and drain path for blockage, flush and clean the trap, and clear any restrictions in the condensate line.
- Inspect the air pressure sensor circuit including the sensor itself, all tubing and hoses, and electrical connectors for damage, blockage, or loose connections.
- Correct any vent installation defects such as incorrect pipe diameter, excessive length, too many elbows, or shared venting that violates code.
- Replace the air pressure sensor if cleaning all filters, vents, and drains does not clear the fault and the sensor circuit shows signs of failure.
Parts Often Needed
| Part | Notes |
|---|---|
| Navien air pressure sensor (APS) | Amazon | Replace when cleaning vents and filters does not resolve the error and sensor circuit is suspect. |
| Navien air filter | Amazon | Common service item that directly clears E010 when clogged. Check your model’s filter location and part number. |
| Condensate trap assembly | Amazon | Replace if trap is cracked, leaking, or cannot be fully cleared of blockage by flushing. |
When to Call a Pro
Call a licensed technician if you are not comfortable working with gas appliances, if the error persists after cleaning the filter and checking obvious vent obstructions, or if you suspect a faulty air pressure sensor or venting code violation. A technician has the tools to measure differential pressure, verify sensor operation, and correct complex venting issues. Any work involving gas connections, combustion diagnostics, or electrical component replacement on a tankless heater should be performed by a qualified professional to maintain warranty coverage and make sure safe operation.