BoilerFaultCodesRavenheat 31 Fault Code
The Ravenheat 31 fault code means: your boiler has detected that the exhaust gases are not being monitored correctly and has shut down for safety.. It appears on 8 Ravenheat models in our database.
Technical description: Failed flue temperature – the flue sensor needs checking or replacing
What causes the Ravenheat 31 fault?
This fault occurs when the boiler's internal safety system can no longer accurately measure the temperature of the exhaust gases leaving the flue. The most common reason is that the sensor itself has degraded or developed a short circuit, causing it to send an incorrect signal to the main control board. If the boiler cannot verify that these gases are within a safe temperature range, it will shut down to prevent potential damage to the internal components.
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 31 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ravenheat 31 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