Test Operation & Troubleshooting & Maintenance 
 
Discharge temperature sensor error 
Suction temperature sensor error 
Compressor internal overload protection 
High discharge protection 
Refrigerant loss protection 
Heat pump-water pump protection 
Solar kit-water pump protection 
Incorrect capacity DIP switch setting 
Communication error between    indoor and outdoor unit 
Drive communication error 
High pressure sensor error 
Enthalpy-enhancing sensor error 
Low pressure sensor error 
Heat exchanger-leaving water temperature sensor error 
Auxiliary heater-leaving water temperature sensor error 
Heat exchanger-entering water temperature sensor error 
Water tank water temperature sensor 1 error 
Water tank water temperature sensor 2 error 
Solar kit-entering water temp sensor 
Solar kit-leaving water temp sensor 
Heat pump-water flow switch 
Solar kit-water flow switch 
Welding protection of the auxiliary heater 1 
Welding protection of the auxiliary heater 2 
Welding protection of the water tank heater 
Under-voltage DC bus or voltage drop error 
AC current protection (input side)