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Navien E110 — Exhaust Blockage
Your Navien detected an exhaust blockage or abnormal air pressure. Something is restricting the intake or exhaust — often a blocked vent, condensate, or a dirty filter.
What E110 Means
E110 means the unit sensed that its intake or exhaust isn't flowing the way it should — an actual blockage, or an air-pressure reading outside the normal range. Because safe combustion depends on moving the right amount of air, the unit locks out until the path is clear.
On the South Shore, the seasonal version of this is a vent termination blocked by snow, ice, leaves, or a nest. Inside, it can be condensate pooling in the vent or trap, a dirty intake filter, or an air-pressure sensor reading wrong. We work outside-in: vent termination first, then condensate, then the sensor.
Common Causes of E110
1. Blocked vent or intake termination
Snow, ice, leaves, insects, or a bird or rodent nest at the outside termination is the classic cause — especially after a storm. Clearing it often restores the unit.
2. Condensate blockage
Condensing units make water. If it pools in the vent or the trap clogs, it restricts airflow and trips E110. We clear and check the condensate path.
3. Dirty air-intake filter
A clogged intake filter chokes airflow enough to read as abnormal pressure. Quick to check and clean.
4. Air-pressure sensor fault
If the physical path is clear, the pressure sensor itself may be misreading. We test it before replacing.
E110 FAQs
Why South Shore homeowners choose Johnson Bros.
Navien showing E110? Check the vent outside first.
After a storm it's often snow, ice, or a nest at the vent termination. Tell us your model and what the outside vent looks like.
Need help fast? Call for urgent plumbing issues. Booking online is best when you want the next open appointment without waiting on the phone.
Can't talk right now? Get a callback.
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Navien showing E110? Check the vent outside first.
After a storm it's often snow, ice, or a nest at the vent termination. Tell us your model and what the outside vent looks like.
Call for urgent help now. Book online when you want the next available fit for your schedule.