The possible causes of insufficient flow of four-pass valves:

1. Air conditioner system leaks, resulting in insufficient refrigerant circulation in the system.

2. When the weather is very cold, the refrigerant evaporation basin is not enough.

3. Four-pass valve and system matching poor, that is, the selection of four-pass valve in the middle flow of large and small system capacity. 4. General system design for compressor downtime after a certain period of four-pass valve before reversing, at this time the high and low pressure to balance, reversing to the middle position will stop.

If the four-pass valve is not in place, the main slider will stop in the middle position, the next time the start, the flow caused by the flow and insufficient. 5. The compressor starts the flow is insufficient, the frequency conversion machine performance is more obvious than the fixed speed machine.