Frigidaire Dishwasher: Replace Temperature Sensor

What the sensor does#

The temperature sensor is a negative-temperature-coefficient (NTC) thermistor: its resistance falls as the water heats. The control board reads it to run the heating element and time the cycle. When it drifts or fails, the board either skips heating (thinking the water is already hot) or waits forever for a temperature it will never read — and throws an ER code.

Tools and safety#

• Tools: Phillips #2 screwdriver (for the kick-plate wiring), a digital multimeter, a towel
• Time: 15-25 minutes · Difficulty: beginner
• Safety: kill the breaker. The sensor is low-voltage, but it wires to a control board running on 120V — never reach into the sump with power on.

Step-by-step#

1. Test the old sensor#

With power off, pull the kick plate (two Phillips screws) and find the sensor's two-wire connector under the tub near the sump. Unplug it and meter the resistance: at room temperature (about 70-75 degrees F) an NTC thermistor reads roughly 10,000-15,000 ohms. Infinite means it is open, near-zero means shorted — either way, replace it. If it reads in range but does not drop when you run hot water over the probe, it has failed internally.

2. Find the probe in the tub#

Open the door and pull the lower rack. The sensor is a small cylindrical probe (about an inch long) in the sump, near the heating element or filter, protruding into the water path. Its wire runs down through the tub floor to the connector you just tested.

3. Remove the old probe#

Release the mounting — Frigidaire uses a push-in clip, a single Phillips screw, or a quarter-turn twist-lock (turn it 90 degrees) depending on model — then draw the probe up and out through the tub. Unplug its connector underneath if you have not already.

4. Fit the new probe#

Feed the new probe down through the mounting hole, lock it in place from inside the tub, and confirm the tip sits in the water path where it can read temperature. Route the wire to the harness underneath and click the connector home.

5. Reassemble and test#

Refit the rack and kick plate, restore power, and run a Normal cycle. The ER code should stay away, the cycle should run its usual 60-90 minutes, and the dishes should come out hot. If it runs much longer than that, run one Sanitize cycle — some models use it to recalibrate the board to the new sensor.

About DishSense (Gallery models)#

Frigidaire Gallery dishwashers pair two sump sensors: the temperature thermistor here, and a turbidity (soil) sensor that reads water clarity to decide when the dishes are clean. They fail independently, but an ER code can come from either. If your display shows a digit after the ER, check your model's data sheet to see which sensor it points to.

When to call a professional#

Call a tech if ER persists after a new sensor (the board's sensor input may be damaged), if you cannot find the sensor on your model, if the wire tore during removal, or if several sensors fail at once, which hints at a board voltage problem.

A quick sanity check on your reading#

Thermistor resistance changes with temperature, so take your measurement at a genuinely cool, room-temperature sensor for the numbers to mean anything — a probe still warm from a recent cycle reads lower and can look failed when it is fine. For a second data point, cup the probe in your hand or run warm water over it and watch the resistance fall smoothly; a good NTC sensor tracks the change, while a dead one sits at a fixed value or reads open.