Dishwasher Water Temperature Troubleshooting

Understanding Dishwasher Water Temperature

For effective cleaning and sanitation, JennAir dishwashers perform best with incoming hot water of 120°F (49°C). Water at this water temperature helps dissolve detergent, break down grease, and supports internal heating functions during certain cycles. When the dishwasher water temperature is too cold, soils can remain, and detergents may not activate fully. For dishwashers with internal heaters, you may notice longer cycles as the dishwasher has to spend time heating the water to the correct temperature. 

Temperature directly affects results: hotter water improves soil removal, reduces spotting and filming, and can enhance drying. When the water is consistently cool, you may notice cloudy glasses, food residue, or longer cycle times as the dishwasher attempts to reach programmed temperatures. 

Settings can vary by cycle. For everyday or heavy-duty loads, select options such as High Temperature when available to boost wash and final rinse heat. For delicate items, select gentler cycles that avoid high-heat settings. Always refer to your model’s Owner's Manual for the temperature-related requirements, cycles, and cycle options.

Common Reasons for Cold Water in Dishwashers

Several things can cause a dishwasher to wash with cold or lukewarm water. Understanding these common factors can help you quickly identify and resolve the problem, especially when you notice dishwasher water temperature is too cold during cycles.

• Hot water supply: If the water supply is not connected to a hot water source, it will fill with cold water.  Ensure the inlet is connected to your home’s hot water line, the valve is fully open, and run the kitchen faucet until the water is hot before starting a cycle.
• Water heater setting: A water heater set below 120°F or a long run from the heater can also result in cooler fills and a dishwasher water temperature too cold for optimal cleaning.
• Internal heating element or sensor issues: Many models use an internal heater to raise water temperature. A failed heating element or temperature sensor can prevent the dishwasher from reaching the target heat, leading to poor cleaning. Signs include unusually long cycles, error codes, or dishes that feel cool at the end of the wash. 

How to Adjust and Monitor Water Temperature

Set up the hot water correctly: First, confirm your home’s water heater is set to at least 120°F. Verify the dishwasher’s hot water inlet is connected and the supply valve is open. On many JennAir models, selecting options like High Temperature or Sani Rinse can raise wash or rinse temperatures; use these for heavily soiled loads when available.

Test the temperature at the tap: Before starting a cycle, run the kitchen faucet  for 30–60 seconds, then fill a cup and measure with a thermometer. Aim for 120°F at the tap. If it is lower, adjust your water heater or consult a professional. Running the faucet immediately before the cycle helps ensure the dishwasher fills with hot water from the start. This step is essential, regardless of whether your dishwasher has an internal water heater.

Ensure the dishwasher receives hot water: Run the hot tap until the water is hot, confirm the connection to the hot water line, open the supply valve fully, verify the water heater setting, and utilize the available high-heat options on your JennAir dishwasher.

If the dishwasher water temperature is too cold and persists, a qualified technician can evaluate the situation and properly diagnose your dishwasher.