High Lockout
E31 on Vokera Pinnacle

Your boiler has detected an electrical fault with the internal sensor that monitors the temperature of the water leaving the unit, preventing it from heating up 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

Short circuit on flow sensor

What causes this fault?

This fault occurs when the electrical connection inside the flow temperature sensor has failed, creating a short circuit that sends an incorrect signal to the boiler's control board. The most common reason is that the sensor's internal component has worn out over time or has been damaged by moisture, meaning the boiler can no longer safely monitor how hot the water is.

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

E30View →E32View →E33View →

Related guides you might find useful

Boiler keeps cutting out

Lockout fault with a reset-needed pattern.

Read →

Yellow or orange flame — CO safety

Safety-critical — turn off, read this.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →