E9 220 — Safety temperature sensor shorted or too high (>130°c)

What does E9 220 mean?

The safety temperature sensor contacts have shorted, or the sensor has detected a temperature exceeding 130°C. This is a critical safety lockout.

• Short circuit in the safety temperature sensor.
• Extreme overheating of the system.
• Defective safety temperature sensor.
• Faulty wiring.

Click steps to track your progress.

1. 1

   Turn off the boiler immediately and allow it to cool down completely.

2. 2

   Ensure the system pressure is correct and all isolation valves are open.

3. 3

   Do not attempt to reset the boiler if the temperature remains high.

4. 4

   Contact a Gas Safe registered engineer urgently to diagnose and rectify the overheating or sensor fault.