Navien 110E Fault Code
The Navien 110E fault code means: your boiler is struggling to breathe properly because the pipework that lets out waste gases or takes in fresh air is blocked or damaged.. It appears on 6 Navien models in our database.
Technical description: Exhaust blockage / Intake air supply exhaust flow err. Exhaust air is blocked due to condensate drain faults, deformed or blocked flue, or exhaust gas entering the air supply pipe.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Navien models that show the 110E fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Navien 110E fault code information on this page is sourced and cross-checked against the official Navien service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026