BoilerFaultCodesIdeal 31 Fault Code
The Ideal 31 fault code means: your boiler has experienced an internal electrical short circuit which has likely blown a protective fuse, causing it to stop working entirely.. It appears on 2 Ideal models in our database.
Technical description: Short-circuiting in the 24 V circuit (three-way valve or connector); check for a short-circuit and replace the F3 fuse in the control panel.
What causes the Ideal 31 fault?
This fault occurs when an internal electrical component, usually the motor that moves between heating and hot water, develops a fault and draws too much power. This surge causes a protective fuse on the main control board to blow, which cuts power to the boiler to prevent further damage. The most common root cause is water or moisture entering the three-way valve motor, causing it to short out.
This issue often surfaces in autumn when the heating is turned on for the first time after summer, as the three-way valve may have seized from lack of use.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ideal models that show the 31 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 31 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026