Kenmore Dishwasher Thermostat Replacement Guide — Cost, Signs & DIY Tips

The thermostat in a Kenmore dishwasher serves as a safety device — specifically, it is a high-limit thermostat that cuts power to the heating element if water temperature exceeds safe operating limits (typically 180–200°F). This prevents tub warping, gasket damage, and potential scalding. On Whirlpool-built Kenmore models (665-prefix), this is a bi-metal disc thermostat mounted on the tub bottom near the heating element. LG-built Kenmore Elite models (722-prefix) often integrate temperature limiting into the electronic control module rather than using a separate thermostat component.

Decode Your Model Number

• 665 — Whirlpool: Bi-metal disc hi-limit thermostat, separate component mounted on the tub floor or sump area near the heating element. Also found: thermistor for temperature sensing (different from the hi-limit thermostat).
• 722 — LG (Kenmore Elite): Temperature limiting is typically handled by the thermistor and control board. No separate hi-limit thermostat on many models.
• 587 — Frigidaire: Separate bi-metal thermostat, similar to Whirlpool design.

Important distinction: The hi-limit thermostat (safety cutoff) is a different component from the thermistor (temperature sensor). The thermostat physically breaks the circuit when temperature is too high. The thermistor sends continuous temperature readings to the control board. If your dishwasher is not heating water at all, the thermistor is more likely the culprit. If it overheats and trips the breaker, the hi-limit thermostat may have failed in the closed position.

Signs Your Kenmore Dishwasher Thermostat Needs Replacement

Hi-limit thermostat tripped (open circuit):

• Heating element does not activate at all — water stays cold throughout the cycle
• Sanitize cycle fails to reach temperature
• Dishes come out cold and greasy
• The thermostat tested with a multimeter shows open circuit at room temperature (should show continuity at room temp)

Hi-limit thermostat failed closed (does not trip):

• Water overheats, producing excessive steam
• Plastic items on the lower rack warp or melt
• The heating element runs continuously without cycling off
• Breaker trips during the heating phase (the element draws too long)

How to test:

1. Disconnect power at the breaker
2. Access the thermostat from below (remove kickplate panel)
3. Disconnect one wire from the thermostat
4. Test with a multimeter set to continuity: at room temperature, the thermostat should show continuity (closed circuit). If it reads open, the thermostat has tripped or failed.
5. If it shows continuity at room temperature, carefully heat it with a hair dryer — it should open (break continuity) at its rated temperature. If it never opens, it has failed closed.

Thermostat Cost Breakdown

This is one of the cheapest dishwasher parts. The thermostat itself is under $35, and replacement is straightforward for anyone comfortable working under the dishwasher.

How to Replace the Thermostat

Whirlpool-based models (665-prefix):

1. Disconnect power at the breaker
2. Remove the lower kickplate panel (2 screws, Phillips #2)
3. Locate the hi-limit thermostat — a small round disc component mounted on the tub bottom or sump housing, near the heating element terminals. It has 2 wire connections.
4. Disconnect both wires (note positions, though typically not polarity-sensitive)
5. Remove the single mounting screw or release the mounting clip
6. Install the new thermostat in the same position. Ensure good thermal contact with the tub surface — if the thermostat does not sit flush, it cannot accurately sense temperature.
7. Reconnect wires, replace kickplate
8. Restore power and run a heated wash cycle. Verify that the water heats properly and the element cycles off appropriately.

Tools required: Phillips #2, multimeter, 1/4-inch nut driver. Total time: 15–25 minutes.

When to DIY vs. Call a Professional

• Bi-metal hi-limit thermostat (665-prefix): Beginner-friendly. Accessible from the kickplate, simple 2-wire connection, takes 15–25 minutes. Excellent first-time repair project.
• LG-based (722-prefix): If your model does not have a separate thermostat, the temperature limiting function is in the control board/thermistor. This is a different repair path — see the sensor or control board replacement guides.
• Call a professional if: The thermostat keeps tripping after replacement. This usually means the heating element is drawing excessive current (partially shorted element) or the water circulation is restricted, causing localized overheating. The thermostat is not the root cause in this scenario.

How Long Does a Kenmore Dishwasher Thermostat Last?

• Bi-metal disc thermostats (665-prefix): 10–20 years. These are simple mechanical devices with no electronics. They either work or they do not.
• When a thermostat trips, it may be a one-time event (power surge caused a temporary overheat condition). Some bi-metal thermostats are resettable — press the small button on the disc. If it stays reset, monitor closely. If it trips again, replace it.

Maintenance Tips

• Ensure the dishwasher's water supply temperature is 120°F — water that is too hot from the home water heater forces the dishwasher's heater and thermostat to work in an already-elevated range
• Keep the heating element free of scale — scale creates hot spots that can trigger the hi-limit thermostat prematurely
• Do not block water circulation in the tub with oversized items — restricted flow creates localized hot zones
• Run a descaling cycle quarterly if you have hard water

Decode Your Kenmore Dishwasher Model Number

Every Kenmore repair starts with identifying the OEM manufacturer from the first three digits of your model number:

• 665 — Whirlpool (most common for Kenmore dishwashers 2000-2020). Uses Whirlpool W10/WP part numbers. Diagnostic mode: press three buttons in sequence within 5 seconds.
• 587 — Frigidaire/Electrolux. Uses Frigidaire-specific parts. Diagnostic: hold Start and Cancel simultaneously.
• 630 — Samsung (newer models). Samsung-specific parts and diagnostics.
• 722 — LG (Kenmore Elite). Uses LG part numbers (EBR prefix). Diagnostic: press Power then Start within 3 seconds.

This decode determines which parts fit your machine, which diagnostic procedures to use, and where to find the best prices. The Kenmore label on the front means nothing for parts sourcing — always reference the OEM part number.

Cost-saving strategy: Once you know the OEM manufacturer, search for the Whirlpool or LG OEM part number directly instead of the Kenmore-branded equivalent. The identical part under the OEM brand name typically costs 30-40% less.

Common Kenmore Dishwasher Error Codes by Platform

Whirlpool-based (665-prefix): F-number/E-number system. F1 E1 (control board), F2 E2 (stuck button), F5 E1/E2 (door switch), F6 E1-E4 (communication), F8 E1 (water inlet), F9 E1 (drain).

LG-based (722-prefix Kenmore Elite): LE/IE (motor/inlet), OE (drain), HE (heater), tE (thermistor), FE (overfill).

Knowing your platform's error codes helps diagnose the failing component before ordering parts.

FAQ

How much does it cost to replace a Kenmore Dishwasher Thermostat?

DIY cost is $10–$35. Professional installation runs $70–$220. One of the cheapest parts — the thermostat itself is under $35 and replacement takes 15–25 minutes.

What is the difference between a thermostat and a thermistor in my Kenmore dishwasher?

The hi-limit thermostat is a safety device that physically cuts power if temperature exceeds safe limits. The thermistor is a sensor that continuously reports temperature to the control board. Different components, different failure modes, different symptoms.

My Kenmore dishwasher is not heating water — is it the thermostat?

Possibly. A tripped hi-limit thermostat breaks the heating circuit. Test with a multimeter at room temperature — it should show continuity. If open, the thermostat is tripped. But also check the heating element and the thermistor, which can produce the same symptom.

Can I reset the thermostat instead of replacing it?

Some bi-metal thermostats have a small reset button. Press it — if it clicks and stays reset, it may work. But a thermostat that tripped once without an obvious cause (like a blocked vent) is likely degrading and should be replaced preventively. At under $35, replacement is cheap insurance.

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