Water Temp High

Disclaimer: The procedures described herein should be performed only by or under the supervision of specialized technicians. LaserStar is not responsible for damage to parts, equipment, or persons attempting to perform any of these procedures without proper supervision or technical assistance, proper tools, or safety measures necessary for laser, high, and low voltage handling.

The Water High Temp error message can have different causes:

1. The laser does not have enough space in the back for hot air to circulate through the exhausts.

2. The heat exchanger fan does not start when the laser requires it

3. The temperature sensor that activates the fan is damaged

4. The control board is damaged

The first step is to rule out that the problem is coming from the control card. To do this, have the Troubleshooting Kit handy and take one of the three 2-pin jumpers inside. 

Now, with the laser off, locate the cable with label 36 on the control board. Disconnect the cable and place the jumper between the two pins.

G1, G2 and G3 Control Board

G4 and G5 Control Board

Now turn on the Laser and confirm if the message appears on the display again. If the message appears, the control board has a fault and needs to be replaced.

If the message does not appear on the display, it is possible that the Heat Exchanger's FAN is not working properly or the temperature sensor is damaged. 

Locate the two sensors first. These sensors are located in the input line of the Heat Exchanger. The two sensors are together, opposite each other. You can also identify one from the other by the color of the wire. Orange is the color of the cable that goes to the control board in J36

How to test the Temp sensor?

A Voltmeter is needed to do this test.

The temperature sensor must be check first. To check the temperature sensor, place the voltmeter to measure continuity.

With the laser off, locate the cable with the label 36 or J36, and disconnect it. It is identified on the control board as "Temp"  

 Once disconnected, identify the two small sheets that are exposed 

Take each tester from the voltmeter and touch the two sheets at the same time. Notice the voltmeter, it should change as shown in the picture 

If this result is obtained, the temperature sensor is good 

How to test the Fan Sensor?

Testing the fan sensor is more complex. Depending on the laser model, the ventilator can operate at 24 VDC or 120–220 VAC, which poses a risk if proper training is not available. In addition, the location of the sensor makes the test even more difficult.

This sensor works more like a switch: it closes when the temperature of the water entering the heat exchanger exceeds 66°C (150°F). In this case, it is best to remove the fan, check the input voltage and test if it turns on.