Your boiler's internal temperature sensor has stopped sending the correct information to the control board, preventing the system from operating safely.

Exchanger probe error – t-sensor damaged, short circuited, sensor damaged or wiring broken

What causes this fault?

This fault occurs when the sensor responsible for monitoring the heat exchanger's temperature fails to communicate with the main control board. The most common reason is that the sensor has physically degraded or developed a short circuit, meaning the boiler can no longer verify if it is operating at a safe temperature. In some cases, the error is caused by loose or damaged wiring connecting the sensor to the brain of the boiler.