If your LG dishwasher isn't getting hot, it's often due to a problem with one of several key components responsible for heating the water, sensing temperature, or controlling the wash cycle. Proper hot water is essential for effective cleaning and sanitization.
Understanding Why Your Dishwasher Needs Hot Water
Dishwashers rely on hot water (typically between 120-150°F or 49-65°C) for several reasons:
- Effective Cleaning: Hot water helps dissolve detergent, emulsify grease, and remove stubborn food particles more efficiently.
- Sanitization: High temperatures kill bacteria and other microorganisms, ensuring your dishes are not just clean but also sanitary.
- Drying: The residual heat from the hot water helps dishes dry faster through evaporation.
When your LG dishwasher fails to heat water, dishes may come out dirty, greasy, or still wet.
Common Reasons for No Heat
Several parts work in conjunction to heat the water in your LG dishwasher. When one of these fails, it can prevent the entire heating process.
1. Defective Electronic Control Board
The electronic control board acts as the "brain" of your dishwasher, managing all operations, including the heating cycle. If this board is defective, it may fail to send power to the heating element or properly regulate the wash cycle, resulting in no hot water. This is a very common reason for heating issues.
2. Faulty Pump and Motor Assembly
The pump and motor assembly is crucial for circulating water throughout the dishwasher tub. If this assembly is faulty, water may not circulate properly over the heating element or reach adequate levels for heating. Inadequate water circulation can prevent the water from reaching the desired temperature, even if the heating element is working. This is another frequent cause of heating problems.
3. Damaged User Interface Control
The user interface control is where you select your wash cycles and options. If this component is damaged, it might not properly communicate your chosen settings (including those requiring hot water) to the main electronic control board. This can lead to the heating cycle not being initiated at all, even if all other components are functional. It is a common point of failure that can impact heating.
4. Failed Heating Element
The heating element is a large, usually exposed, coiled component at the bottom of the dishwasher tub. Its primary job is to heat the water to the desired temperature. If the heating element is burned out or otherwise damaged, it won't be able to warm the water.
5. Malfunctioning High Limit Thermostat or Thermistor
The high limit thermostat (or a thermistor in newer models) monitors the water temperature inside the dishwasher.
- High Limit Thermostat: This is a safety device that prevents the dishwasher from overheating. If it fails, it may incorrectly sense that the water is too hot and cut power to the heating element, or it might simply fail open, preventing the element from ever turning on.
- Thermistor: A thermistor provides more precise temperature readings to the control board. If it's faulty, the control board might receive inaccurate temperature data, leading it to either not activate the heater or activate it at the wrong times.
6. Blown Thermal Fuse
A thermal fuse is a safety device designed to protect the dishwasher from overheating. If the dishwasher gets too hot for any reason, the thermal fuse will blow, cutting off power to prevent damage. A blown thermal fuse will prevent the heating element, and often the entire dishwasher, from operating.
7. Issues with the Water Inlet Valve or Water Level
The dishwasher needs to fill with the correct amount of water for the heating element to function properly.
- If the water inlet valve is clogged or malfunctioning, the dishwasher might not fill with enough water.
- If there's insufficient water in the tub, the heating element may not activate as a safety precaution, or it won't be able to effectively heat the small amount of water present.
Troubleshooting Steps & Solutions
Before calling for service, you can perform a few basic checks:
1. Check Wash Cycle Settings
Ensure you've selected a wash cycle that includes a heated wash or sanitize option. Some cycles, especially "Quick Wash" or "Rinse Only," may not include a heating phase.
2. Verify Hot Water Supply
- Kitchen Faucet Check: Run the hot water at your kitchen sink (closest to the dishwasher) for a minute or two before starting a dishwasher cycle. This ensures that hot water is already in the supply line, rather than cold water that the dishwasher would then have to heat.
- Water Heater Settings: Confirm your home's water heater is set to at least 120°F (49°C).
3. Inspect the Heating Element
Visually inspect the heating element at the bottom of the tub for any signs of damage, such as cracks, breaks, or burn marks. A damaged element will need replacement.
4. Consult Your User Manual
Your LG dishwasher's user manual often contains specific troubleshooting tips and error codes that can help diagnose heating issues. You can usually find a digital copy on the LG Support website. (Note: This is a placeholder link for demonstration purposes; actual URL may vary.)
5. Professional Assistance
For issues involving the electronic control board, pump and motor assembly, user interface control, high limit thermostat, or thermal fuse, it's generally best to contact a qualified appliance repair technician. These components often require specialized tools and electrical knowledge for safe and effective diagnosis and replacement.
Troubleshooting Guide
| Symptom | Potential Cause(s) | Recommended Action |
|---|---|---|
| Dishes not clean, cold after cycle | Failed Heating Element, Defective Electronic Control Board, Malfunctioning High Limit Thermostat/Thermistor | Inspect element, check wash settings, call technician for board/thermostat. |
| Dishwasher not starting or no power | Blown Thermal Fuse, Damaged User Interface Control | Check for fuse issues (professional recommended), verify power supply, call technician for user interface. |
| Water not draining or insufficient circulation | Faulty Pump and Motor Assembly | Clear drain filter, check for obstructions, call technician for pump/motor issues. |
| Water stays cold throughout cycle | All of the above, Water Inlet Valve/Water Level Issue | Verify hot water supply, check for proper fill level, professional diagnosis for internal components. |
Resolving a heating issue in your LG dishwasher often requires identifying the specific faulty component. While some checks can be done at home, diagnosing and replacing internal electrical parts typically requires professional expertise.
