Your boiler has lost connection with the sensor that monitors the outdoor temperature, making it difficult for the system to adjust its heat settings efficiently.

Outside Sensor Fault

What causes this fault?

This fault occurs when the boiler's main control board can no longer communicate with the external sensor mounted on the outside of your home. The most common reason is damage to the thin communication wires by pests or garden maintenance, or water entering the sensor housing and causing corrosion. Because the boiler no longer knows how cold it is outside, it cannot automatically adjust its temperature to save you money on your energy bills.