Air conditioning systems with expansion valve Troubleshooting Procedures parti 1 Correct evaluation of the pressure manometer display is particularly important. Here are some examples: 1- Low pressure: hoch High pressure: high Outflow temperature at the centre vent: higher, up to ambient temperature Possible causes: engine overheated, condenser contaminated, condenser fan defective-incorrect direction of rotation, system overfilled 2- Low pressure: normal to occasionally low High pressure: high, occasionally Outflow temperature at the centre vent: higher, possibly fluctuating Possible causes: expansion valve stuck, occasionally closedzXDF 3- Low pressure: normal "> High pressure: high Outflow temperature at the centre vent: slightly higher Possible causes: filter dryer aged, condenser contaminated 4- Low pressure: hoch High pressure: normal to high Outflow temperature at the centre vent: higher depending on bottleneck Possible causes: line from condenser to expansion valve narrowed 5- Low pressure: normal High pressure: normal Outflow temperature at the centre vent: higher Possible causes: too much refrigerant oil in the system kandi younes