A8 — sensor communication error

What does A8 mean?

There is a break in communication to the FX sensor controls. This indicates an electrical connection issue preventing proper sensor operation.

• Loose or damaged electrical connections to the FX sensor.
• Defective FX sensor.
• Control board malfunction.

Click steps to track your progress.

1. 1

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

2. 2

   Visually inspect any accessible sensor connections for looseness or damage.

3. 3

   If the error continues, a Gas Safe registered engineer should check the electrical connections and sensor.