BoilerFaultCodesNavien 117 Fault Code
The Navien 117 fault code means: your boiler has detected that the water pressure inside the system has risen too high, causing it to shut down for safety.. It appears on 1 Navien model in our database.
Technical description: Water pressure too high: Dry fire protection: Water pressure too high
DIY fix possible
Locate the external filling loop, which is a silver braided hose connecting two pipes near the boiler.Ensure both valves on the filling loop are firmly closed to stop more water from entering the system.Bleed one or two radiators in the house to release excess water pressure until the boiler's pressure gauge drops back into the green zone.
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Navien models that show the 117 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Navien 117 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 7 July 2026