Q: What cause the white light blink 3 time?

A: The PLC get the signal from the sensor what the water pressure is too low.

There are two reasons which may cause this.

1. The water pressure is low.

2. The sensor send the wrong signal.

For the first one, we just need to make sure the water pressure is more than 40PSI during the machine running.

For the second one, we can disconnect the '0100' line which is the signal between the sensor and the PLC and run the machine. If the machine can run without any problem, we can know the sensor is bad.