Vaillant · ecoTEC plus Boilers
The boiler has detected a short circuit in the tank NTC (Negative Temperature Coefficient) sensor, which is used for domestic hot water. This indicates a fault with the sensor or its wiring, leading to incorrect temperature readings.
Click steps to track your progress.
Reset the boiler by pressing the reset button.
Power off the boiler, wait a moment, then power it back on.
If the error persists, contact a qualified service technician to inspect or replace the tank NTC sensor and its wiring.