E9 318 — Flue gas temperature sensor contacts interrupted

What does E9 318 mean?

The contacts of the flue gas temperature sensor have been interrupted. This means the boiler cannot accurately monitor flue gas temperatures for safe operation.

• Loose or disconnected wiring to the flue gas temperature sensor.
• Damaged sensor wiring.
• Defective flue gas temperature sensor.

Click steps to track your progress.

1. 1

   Power cycle the boiler by turning off the main power for 30 seconds, then restart it.

2. 2

   Visually inspect the wiring connections to the flue gas temperature sensor to ensure they are secure.

3. 3

   If the issue continues, contact a Gas Safe registered engineer to diagnose and repair the sensor or its wiring.