High Lockout
F012 on Intergas Xclusive 24

Your boiler has detected an issue with a temperature sensor that is preventing it from heating your home or water safely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Sensor fault S5.

What causes this fault?

This fault occurs when the boiler's internal control system loses communication with the S5 temperature sensor or receives an incorrect reading. The most common reason is a physical failure of the sensor's internal components or a loose connection in the wiring harness that links the sensor to the main control board.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer
Search the official register →

Related fault codes

F010View →F011View →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →