Fault B8 (Detailed 141) — Burner blocked due to flue gas sensor cable broken

What does B8 mean?

The boiler's burner is blocked because the cable connected to the flue gas temperature sensor is broken. This prevents the boiler from accurately monitoring flue gas temperatures, causing a safety shutdown.

• Flue gas temperature sensor cable broken

Click steps to track your progress.

1. 1

   Visually inspect the cable connected to the flue gas temperature sensor for any signs of damage or breaks.

2. 2

   Ensure the cable is firmly connected at both the sensor and the boiler's control unit.

3. 3

   Press the reset button R on your boiler.

4. 4

   If the fault persists, contact a qualified service technician to repair or replace the cable or sensor.