BoilerFaultCodesRavenheat 31E Fault Code
The Ravenheat 31E fault code means: your boiler is having trouble 'talking' to your smart thermostat or external heater controls, meaning it may not receive instructions to turn on or off.. It appears on 7 Ravenheat models in our database.
Technical description: OpenTherm (OT) communication error
What causes the Ravenheat 31E fault?
This fault occurs when the digital connection between your external thermostat and the boiler's internal computer is broken or interrupted. The most common reasons are loose wiring connections at either end of the control cable or a electronic synchronization failure between the two devices.
DIY fix possible
Check that your smart thermostat or wall controller is powered on and has working batteries.Ensure the thermostat bridge or hub is plugged in and connected to your Wi-Fi.Try restarting your boiler at the main isolation switch to reset the connection.
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Gas Safe Register →Ravenheat models that show the 31E fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ravenheat 31E 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