Thermann Fault Code 721
Fault: False flame detection.
Applies to: Thermann TH32END5N, TH32END5L, TH32END6N, TH32END6L Units
When a failure occurs, information relating to the error flashes on the Status Display or optional Remote Controller. At the same time, a buzzer will be used. To stop the buzzer sound, the Operation button must be turned off. If this occurs, take appropriate measures.