High
E05 on Heatline Sargon 24

Your boiler has detected a problem with the internal sensor that monitors the temperature of the water used to heat your radiators, preventing the system from running 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

CH flow thermistor fault: The central heating flow NTC sensor is damaged or disconnected.

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

E06View →

Related guides you might find useful

Radiators cold at the bottom

Sludge build-up — needs flushing, not bleeding.

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 →