Error Code
high
Hobart LXe – LXe Will Not Drain
On your LXe SERIES DISHWASHERS unit, a "machine will not drain" issue…
Hobart LXe - Error WASH TEMP SENSOR: Wash Thermistor Error
Caution / Monitor Closely
Warning: The information provided here is for educational purposes only.
Working with commercial kitchen equipment involves high voltage, gas, and high temperatures.
We strongly recommend contacting a certified service technician for any repairs.
We are not responsible for any damage or injuries resulting from DIY repair attempts.
This information is provided 'as is' without any guarantees of completeness or accuracy.
TLDR
On your LXe SERIES DISHWASHERS unit, the WASH TEMP SENSOR error indicates the wash temperature probe is registering outside its normal operating range, potentially due to an open or short circuit. This compromises proper wash temperature regulation, affecting sanitization. Begin by visually inspecting the sensor and its wiring connections for any damage or dislodgement.
Technical Details
Repair Steps:
- Power Cycle and Initial Check: First, power off the dishwasher at the main disconnect for at least 60 seconds, then power it back on to reset the control system. Observe if the error re-appears. If the machine continues to operate, use an external calibrated thermometer to manually verify the actual wash tank temperature and compare it to the display reading (if available).
- Inspect Wash Temperature Sensor and Wiring: Locate the wash temperature sensor (thermistor), typically immersed in the wash tank or connected to a well. Carefully inspect the sensor’s physical condition for any signs of damage, corrosion, or scale buildup. Follow the sensor’s wiring harness back to the control board, checking for any cuts, pinches, loose connections, or burnt sections. Ensure all connectors are securely seated.
- Test Sensor Continuity/Resistance: With power disconnected, use a multimeter to test the resistance of the thermistor. Consult your Hobart LXe series service manual for the expected resistance values at various temperatures. An “OPEN” reading indicates a broken circuit, while a very low or “SHORT” reading suggests an internal short. Compare the readings to specifications.
- Examine Control Board Connections: Trace the sensor wires to their termination point on the main control board. Disconnect and re-seat the connector, inspecting the pins on both the connector and the board for any corrosion, bending, or signs of overheating. A faulty connection at the board could mimic a sensor error.
- Replace Faulty Wash Temperature Sensor: If the sensor’s resistance test indicates it’s out of specification or if visible damage is present, replace the wash temperature sensor with a genuine Hobart LXe series replacement part. Ensure proper sealing during installation to prevent leaks.
- Verify Software/Firmware (Advanced): In rare cases, outdated or corrupted firmware can lead to sensor misinterpretation. If all hardware checks pass, consult your Hobart service manual or a certified technician for information on checking and potentially updating the dishwasher’s software.
- Consult a Certified Hobart Technician: If, after performing these steps, the error persists, there may be an issue with the main control board or other complex electrical components. Contact a certified Hobart service technician for further diagnosis and repair.
Common Questions:
Q: Can I continue to use my HOBART LXe SERIES DISHWASHERS with a WASH TEMP SENSOR error?
A: While the machine may continue to run cycles, it is strongly advised against continuous use. The wash temperature sensor is critical for ensuring proper sanitization and effective dishwashing. Operating without accurate temperature control can lead to dishes not being cleaned or sanitized to health code standards.
Q: What is a wash temperature sensor (thermistor) and why is it important?
A: A wash temperature sensor, often a thermistor, is a device that measures the temperature of the water in the wash tank and sends this data to the dishwasher’s control board. It’s crucial for maintaining the correct wash temperature required for effective cleaning and sanitization, preventing bacterial growth, and ensuring detergent efficiency.
Q: How can I prevent the WASH TEMP SENSOR error in the future?
A: Regular preventive maintenance is key. This includes periodic inspection of the sensor for scale buildup and damage, ensuring proper descaling of the machine, and checking wiring connections for integrity. Following recommended cleaning and maintenance schedules for your HOBART LXe SERIES DISHWASHERS can help extend component life.
When to call a technician
Consider calling a certified technician if:
- The error keeps coming back after you've tried the steps above.
- You're not comfortable doing the checks or repairs yourself.
- You notice unusual noise, smell, or behaviour.
- Equipment is under warranty and you want official service.
- You need the unit back in service quickly with minimal downtime.