BoilerFaultCodesRavenheat E31 Fault Code
The Ravenheat E31 fault code means: your boiler has lost its digital connection with your external smart thermostat or heating controls, meaning it cannot receive instructions to turn on.. It appears on 9 Ravenheat models in our database.
Technical description: OpenTherm communication error
What causes the Ravenheat E31 fault?
This fault occurs when the digital 'conversation' between your boiler and your smart thermostat is interrupted, leaving the boiler without instructions. The most common reasons are a loose connection in the control wiring, a software glitch in the thermostat unit, or a complete failure of the communication module inside the boiler.
DIY fix possible
Check that your external thermostat or wall control is powered on and has fresh batteriesEnsure the wires connecting your thermostat to the boiler haven't been accidentally bumped or damagedTurn the boiler off at the main power switch, wait 30 seconds, and turn it back on to reset the connection
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Gas Safe Register →Ravenheat models that show the E31 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ravenheat E31 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