KitchenAid Dishwasher Temperature Not Right — Too Cold or Too Hot

Temperature control in your KitchenAid dishwasher directly affects cleaning performance, sanitization, drying effectiveness, and energy efficiency. When water is too cold, detergent does not activate fully and grease remains. When water overheats, plastics can warp, delicate items may be damaged, and the thermal fuse may trip — stopping the cycle entirely.

KitchenAid KDTM and KDTE models target specific temperatures for each cycle phase: pre-rinse at incoming temperature (no heating), main wash at 130–140F, Sanitize Rinse at 155F minimum (required by NSF certification), and drying with the element running until tub air reaches approximately 170F. The system relies on the thermistor (integrated into the turbidity sensor on most models) to report actual water temperature to the control board.

Diagnosing Temperature Problems

Water Too Cold

Symptoms: Greasy dishes, detergent residue on dishes (tablet not fully dissolved), Sanitize Rinse light does not illuminate at cycle end (did not reach required temperature), items cold and wet at cycle end.

Common causes:

1. Low incoming water supply temperature — The dishwasher heater is a booster, designed to add 20–30F. If your hot water arrives below 110F, the dishwasher cannot reach wash targets in time.
2. Failed heating element — Open circuit means no heat generation. Test at element terminals: 15–30 ohms normal, infinite (OL) means burned out.
3. Thermistor reading high — An NTC thermistor that drifts high-resistance at wash temperatures tells the board the water is colder than it actually is. The board tries to heat longer, which does not help if the element is also failing — or the extended heat time exceeds the maximum and the board times out with F8E6.
4. Control board relay — The heater relay on the main board (W11413276) may not be closing when commanded.

Water Too Hot

Symptoms: Plastic items warped or melted, excessive steam from door vent, thermal fuse tripping (complete shutdown), element glowing visibly through the tub bottom (should not be visible during normal operation).

Common causes:

1. Thermistor failed low-resistance — Reports water as colder than actual, causing the board to keep the element running past target temperature.
2. Control board relay stuck closed (welded) — The relay that powers the element is physically stuck in the closed position, keeping the element energized continuously regardless of temperature.
3. Element shorted to ground — A ground fault can cause uncontrolled heating in sections of the element.

Testing the Thermistor

The thermistor on most KitchenAid dishwashers is an NTC type integrated into the turbidity sensor assembly in the sump area. NTC means resistance decreases as temperature increases.

Expected readings:

• At room temperature (72F): approximately 50,000 ohms (50K)
• At wash temperature (130F): approximately 10,000–15,000 ohms
• At sanitize temperature (155F): approximately 6,000–8,000 ohms

Test procedure:

1. Disconnect power at breaker.
2. Locate the turbidity sensor in the sump (remove filter assembly first). Disconnect its wiring connector.
3. Measure resistance between the thermistor pins on the sensor (refer to wiring diagram on tech sheet for which pins).
4. At room temperature, you should read approximately 50K ohms. Significantly higher (100K+) indicates a drifted sensor reading cold. Significantly lower (below 20K at room temp) indicates a drifted sensor reading hot.
5. If out of range, replace the entire turbidity/thermistor sensor assembly.

Parts Cost: $25–$55 | Professional Repair: $120–$200

Testing the Heating Element

1. Disconnect power. Access element terminals behind the toe plate.
2. Disconnect both wires from the terminal studs.
3. Multimeter between terminals: 15–30 ohms = good. OL (infinite) = open circuit, element is burned out.
4. Multimeter from each terminal to element sheath (metal body): should read OL (infinite). Any resistance reading = ground short.

Parts Cost: $25–$55 | Professional Repair: $130–$220

The Sanitize Rinse Temperature Requirement

KitchenAid dishwashers with Sanitize Rinse must reach 155F during the final rinse to earn NSF certification for bacterial elimination. The Sanitize indicator light at cycle end confirms this temperature was achieved. If the light does not illuminate:

• The incoming water was too cold for the booster to compensate.
• The element is weakening (heating slowly) and the maximum allowed heating time expired before reaching 155F.
• The thermistor is reading hot (telling the board target was reached when it was not — in this case the light would illuminate falsely, which is harder to detect).

To verify actual temperature, place an oven thermometer in a cup on the upper rack and run a Sanitize Rinse cycle. Check the temperature immediately at cycle end.

Adjustments and Solutions

• Run kitchen hot tap 30–60 seconds before starting — clears cold water from the supply line.
• Verify water heater setting — should be 120F minimum at the tap.
• Select High Temp Wash option for cycles where maximum cleaning is needed — this tells the board to boost to a higher target.
• If element is weakening (takes too long to heat but eventually gets there), replace it proactively before complete failure.
• If relay is stuck (overheating), disconnect power immediately and replace the control board. A stuck-on element is a fire hazard.

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KitchenAid dishwasher temperature issues? Our technicians carry multimeters and replacement sensors, elements, and boards for complete thermal system diagnosis. Schedule a repair →