Bosch · Alarm List A/W Split (8754) 2018 01 10
An alarm is triggered if the hot water sensor TW1 circuit is continuously broken or shorted for 15 minutes, or if 3 warnings have occurred within 3 hours.
Click steps to track your progress.
Refer to possible causes and actions for warning codes 5237 and 5238.
Check the TW1 sensor and its wiring for damage.
Contact a qualified technician.