Medium
47 on Alpha E-Tec R

Your boiler is currently running at a lower power because it has detected that the exhaust gases are getting too hot, serving as a warning before it shuts itself down completely.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Flue thermostat has sensed high flue gas temperature (105°C) and reduced the burner output to prevent damage. If the temperature continues to rise the boiler will lock out and E03 will be displayed

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 →

Related fault codes

E03View →

Related guides you might find useful

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Radiators cold at the bottom

Sludge build-up — needs flushing, not bleeding.

Read →