BoilerFaultCodesRavenheat 23E Fault Code
The Ravenheat 23E fault code means: your boiler has detected a problem with the sensor that monitors exhaust gases, and it has shut down as a safety precaution.. It appears on 7 Ravenheat models in our database.
Technical description: Flue sensor damaged
What causes the Ravenheat 23E fault?
This fault occurs when the internal sensor responsible for monitoring the temperature of the exhaust gases becomes faulty or loses its connection to the control board. The boiler shuts down as a safety measure to prevent the appliance from overheating or operating with unsafe flue gas temperatures. The primary cause is typically a degraded NTC sensor or heat damage to the wiring harness connected to it.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Gas Safe Register →Ravenheat models that show the 23E fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ravenheat 23E fault code information on this page is sourced and cross-checked against the official Ravenheat service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026