LG Dishwasher HE Error Code: Troubleshooting and Repair Guide
If you see the LG dishwasher HE error code flashing on your display, it indicates a malfunction within the appliance’s heating system. This code specifically alerts you that the dishwasher is unable to heat water to the required temperature or, conversely, that the water has become dangerously hot.
Addressing this issue promptly is essential, as proper water temperature is critical for sanitizing dishes and dissolving detergent effectively. This guide provides a professional technical analysis of the problem, covering the inspection of the heating element, thermistor, and control board to restore your appliance to working order.
Understanding the LG Dishwasher HE Error Code
The LG dishwasher HE error code is a safety and performance notification triggered by the main circuit board. It activates under two specific conditions:
- No Heat: The water fails to reach the necessary wash temperature (typically around 120°F to 140°F) after a set period.
- Overheating: The thermistor detects that the water temperature has exceeded a safety threshold (often above 194°F), which shuts the unit down to prevent damage.
While a simple software glitch can sometimes cause this, it usually points to a hard failure in the heating circuit.
Common Causes of the HE Error
Before disassembling the unit, it is helpful to understand the components likely responsible for the failure:
- Heating Element: The most common culprit. If the element burns out or suffers a physical break, it cannot generate heat.
- Thermistor: This temperature sensor changes resistance based on water heat. If it fails, it sends incorrect data to the control board.
- Wiring Harness: Vibrations and heat can damage wires, particularly those connecting the heater and the main board.
- Control Board: The heater relay on the board controls the voltage sent to the heating element. If this relay sticks or fails, the heater may never turn on or never turn off.
NOTE: You can also check out common fixes for frequently encountered LG dishwasher error codes—like: LG dishwasher not draining OE, LG dishwasher IE error no water
Troubleshooting the LG Dishwasher HE Error Code
Follow these steps to diagnose and repair the issue.
Safety Warning: Before performing any multimeter tests or internal inspections, always disconnect the power supply by unplugging the dishwasher or flipping the circuit breaker. Shut off the water supply valve to prevent leaks during repair.
1. Preliminary Checks
Before opening the machine, verify the external factors:
- Incoming Water Temperature: Run the hot water tap at the kitchen sink for a minute. The water entering the dishwasher should be at least 120°F. If the water is too cold, the heating element may time out trying to heat it, triggering the error.
- Hard Reset: Turn off the power supply to the dishwasher for 60 seconds. Restore power and run a cycle. If the code clears, it may have been a temporary logic glitch.
2. Testing the Heating Element
The heating element is a resistive coil that heats the water. You will need a multimeter to perform a continuity test.
- Access the heating element by removing the bottom kick plate or pulling the dishwasher out to reach the underside.
- Locate the two terminals of the heating element.
- Disconnect the wires attached to the terminals to isolate the component.
- Set your multimeter to the lowest Ohms (Ω) setting.
- Place the probes on the heater terminals.
- Normal Reading: You should see a resistance between 10 and 30 ohms (typically around 11-15 ohms for most LG models).
- Faulty Reading: If the meter reads “OL” (Open Loop) or infinity, the element is broken and requires replacement.
3. Inspecting the Thermistor
The thermistor is a sensor that monitors water temperature. If the resistance values are out of spec, the main board will assume a heating failure.
- Locate the thermistor, typically found in the sump assembly near the heating element.
- Disconnect the wiring harness connected to the sensor.
- Measure the sensor resistance with your multimeter.
- At Room Temperature (approx. 77°F / 25°C): The resistance should generally fall between 11kΩ and 14kΩ (11,000 to 14,000 ohms).
- Test: You can remove the thermistor and hold it in your warm hand; the resistance should drop as the temperature rises.
- If the resistance is static or reads zero/infinity, the thermistor is defective.
4. Checking the Wiring Harness and Connections
Visually inspect the wiring harness running from the bottom of the tub to the door and the main control board.
- Look for burnt connectors, melted insulation, or pinched wires.
- Corrosion on the heater terminals can create high resistance, mimicking a failed heater. Clean any corrosion with a wire brush or replace the terminals if necessary.
5. Diagnosing the Control Board
If the heating element and thermistor test okay, the issue likely lies with the control board (PCB).
- Heater Relay: Locate the heater relay on the circuit board. Look for signs of soldering burns or discoloration around the relay.
- Voltage Test: A professional test involves checking for 120V AC output to the heater during a cycle. Note: This requires live voltage testing and should only be performed by a qualified technician.
- If the board is not sending voltage to the heater despite receiving a signal from the thermistor, the heater relay is likely failed, and the entire board may need replacement.
Summary
The LG dishwasher HE error code is a specific indicator of temperature regulation failure. By systematically testing the heating element for continuity, verifying the sensor resistance of the thermistor, and inspecting the wiring harness and control board, you can isolate the root cause. While many of these repairs are manageable for DIY enthusiasts, dealing with the power supply and live circuits always demands caution. If you are unsure about interpreting multimeter readings, consult a professional appliance repair specialist.
Frequently Asked Questions
What does the HE error code specifically mean on an LG dishwasher?
The HE code stands for a “Heating Error.” It is triggered when the main control board detects that the water is either not heating up fast enough (failing to reach 120°F–140°F) or has become too hot (exceeding 194°F), which poses a safety risk.
Can I fix the HE error code by just resetting the dishwasher?
In some cases, a minor software glitch can trigger the code. You can attempt a “hard reset” by unplugging the dishwasher or turning off its circuit breaker for 60 seconds. If the code reappears after restoring power and starting a new cycle, the issue is likely a hardware failure that requires repair.
How can I tell if my heating element is actually broken?
The most reliable way to test the heating element is by using a multimeter to check for continuity. After disconnecting power to the unit, test the heater terminals; a functional LG heating element should show a resistance reading between 11 and 30 ohms. If the multimeter reads “OL” or infinity, the element is “open” and must be replaced.
Does the temperature of my kitchen sink water affect the HE error?
Yes. If your home’s hot water heater is set too low, the dishwasher may struggle to raise the water temperature to the required level within the allotted time. It is recommended to run the hot water tap at your sink before starting a cycle to ensure the water entering the dishwasher is at least 120°F.
Is it safe to continue using the dishwasher while the HE code is flashing?
No. When the HE code is active, the dishwasher will typically stop running to prevent damage to the appliance or your dishes. Furthermore, without proper heat, the dishwasher cannot effectively sanitize your dishes or dissolve detergent, leading to poor cleaning results.
