Bosch · Heat Pumps
The Heat Pump has detected a fault with the primary flow sensor (T0). This alarm indicates that the sensor or its signal cable has either failed or short-circuited after multiple warnings.
Click steps to track your progress.
Visually inspect the flow sensor T0's cable and its connection point to the Heat Pump for any signs of damage or dislodgement.
Ensure that any accessible screw terminals for sensor T0 on the control board are snug (do not overtighten).
Power cycle your Heat Pump by turning off the dedicated circuit breaker for at least 30 seconds, then turning it back on.
If the alarm persists, contact a qualified Bosch service technician for further diagnosis and potential component replacement.