BoilerFaultCodesAlpha 31 Fault Code
The Alpha 31 fault code means: your boiler has lost its connection with the thermostat or control panel, meaning it cannot receive instructions to turn on or off.. It appears on 25 Alpha models in our database.
Technical description: Loss of communication with external control (Alpha Climatic)
What causes the Alpha 31 fault?
This fault occurs when the boiler and your thermostat can no longer 'talk' to each other, often due to physical interference or a hardware failure. The most common reason is that the batteries in your room thermostat have died or the wireless receiver attached to the boiler has lost its signal. In some cases, it may be caused by a faulty circuit board that is unable to process incoming signals from your controls.
DIY fix possible
Check if the batteries in your Alpha Climatic room thermostat need replacing.Ensure the thermostat is within range of the boiler and has not been moved.Try restarting the boiler using the reset button to refresh the connection.
Find a Gas Safe engineer
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A cover plan would handle faults like 31: no call-out fees, no surprise bills.
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Alpha models that show the 31 fault code
Click a model for the full fault code list and model-specific repair notes.
- 240XE Repair: £150-300
- CD18 / CD24 Repair: £100-£200
- Cd50s Cd70s Repair: £120-180
- E-Tec 28 Repair: £80-150
- E-Tec 33 Repair: £80-150
- E-Tec NX Repair: £120-250
- E-Tec NXS Repair: £120-250
- E-Tec Plus Repair: £120-250
- E-Tec Plus 10 / 18 Repair: £0-120
- E-Tec Plus 28 Repair: £120-250
- E-Tec Plus 33 Repair: £120-250
- E-Tec Plus NX Repair: £80-180
- E-Tec Regular Repair: £90-180
- E-Tec S Repair: £100-250
- Eco Repair: £90-180
- Eco 11 13 Repair: £0-180
- Evoke Repair: £100-200
- Evoke 10 / 18 Repair: £90-250
- Evoke NX Repair: £120-250
- Intec 40GS2 Repair: £120-220
- Intec 50CS Repair: £90-180
- Intec S Repair: £120-250
- Intec2 25 28XE Repair: £120-250
- Intec2 30SE Repair: £120-250
- SY9 24 Repair: £120-200
Source
Alpha 31 fault code information on this page is sourced and cross-checked against the official Alpha service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026