CC 800 — Outdoor sensor defect

What does CC 800 mean?

The outdoor temperature sensor, if connected, is defective. This sensor helps the boiler adjust its output based on external temperatures.

• Defective outdoor temperature sensor.
• Damaged or loose connecting lead for the sensor.

Click steps to track your progress.

1. 1

   Power cycle the boiler by turning it off at the mains for 30 seconds and then back on.

2. 2

   Visually inspect the outdoor sensor and its connecting cable for any damage or disconnections.

3. 3

   If the issue persists, contact a qualified heating engineer to test and replace the sensor if necessary.