InstallationsDomestic air conditioner11.3 Problem Symptoms and MeasuresSymptom Check Item Details of MeasureNone of the unitsoperatesCheck the power supply. Check to make sure that the rated voltage is supplied.Check the indoor PCB Check to make sure that the indoor PCB is brokenOperationsometimes stops. Check the power supply. A power failure of 2 to 10 cycles can stop air conditioneroperation.Equipmentoperates butdoes not cool, ordoes not heat(only for heatpump)Check for faulty operationof the electronicexpansion valve.Set the units to cooling operation, and compare thetemperatures of the liquid side connection pipes of theconnection section among rooms to check the opening andclosing operation of the electronic expansion valves of theindividual units.Diagnosis by service portpressure and operatingcurrent.Check for insufficient gas.Large operatingnoise andvibrations Check the installationcondition.Check to make sure that the required spaces forinstallation (specified in the Technical Guide, etc.) areprovided.36
