Nefit Bosch storing A01 / 5378 / 5450 / 5451

"5378 Warning Z1 Outdoor unit defrost failure: "Warning if the gaseous refrigerant temperature TR7 < 2°C for 10 seconds, or if TR7 < -1°C for 1 second, in defrost mode. When the warning is given the compressor stops. Then the heat pump will return to normal operation for 10 minutes. Next, the heat pump will start another defrost cycle and the warning will be automatically reset." | 5450 Warning Z1 Condensate drain blocked: "Value of temperature sensor TA4 does not increase in accordance with specification, after completed defrost." Possible cause: "Heating cable in condensate drain is defective and drain is frozen." | 5451 Alarm Z1 Too low flow rate during defrosting: "Alarm if temperature difference TC0-TC3 > maximum delta, for more than 30 seconds and the liquid line temperature TR4 < 0 °C.""