... . Apply 8 bit microcomputer of NEC or Toshiba to controller b. The precision of temperature control <=1°C c. The ... module or LCD(backlight) d. It can control valve, electric heater etc. e. The current loop communication is applied between touch ... etc. h. It has leak current, no water, overflow, over temperature, sensor fault, water pump fault protection etc. Controller for solar type water heater