Troubleshooting Kenmore Error Code Er rt: What It Means & How to Fix

In the field, I’ve seen this lead to erratic cooling cycles, unusual fan noises, or even the ice maker acting up because the logic board is flying blind. It might seem like a catastrophic failure when the display starts flashing, but take a breath. This is a straightforward sensor issue that we can diagnose and repair with a bit of patience and the right approach. Let’s get your kitchen back to normal.

Symptoms of an Er rt Fault

When that “Er rt” code pops up, the refrigerator isn’t just complaining for no reason; you’ll likely notice several physical performance issues. First and foremost, the digital display will flash the error code, often disabling the dispenser or temperature controls. You might notice the refrigerator runs constantly or, conversely, fails to kick the compressor on at all because it doesn’t know if the room is 60 degrees or 90 degrees.

Furthermore, you might hear the internal fans cycling at odd intervals. If the sensor is sending “garbage” data, the control board might think the room is excessively hot, forcing the unit into a high-performance cooling mode that results in frozen milk or lettuce in the fresh food section. In some Kenmore models, you might even notice the water from the dispenser feels lukewarm because the unit has prioritized “survival cooling” over secondary features.

Troubleshooting & Replacement Instructions

1. Power Down and Safety First: Before you touch a single screw, pull the refrigerator away from the wall and unplug it. Working on live circuits is a rookie mistake that can fry the control board or, worse, give you a nasty shock. Wear work gloves to protect your hands from sharp metal edges on the back panels.

2. Locate the RT Sensor: On most Kenmore (especially LG-manufactured) units, the Room Temperature sensor is located under a small plastic vented cover on the top of the refrigerator, often near the door hinge or the top control panel. Use your Phillips head screwdriver to remove the single screw holding this cover in place. Carefully pry it off to reveal the small, bulb-like sensor.

3. The Multimeter Test: This is where we separate the parts-changers from the mechanics. Set your multimeter to the Ohms (Ω) setting (20k range). Unplug the sensor from its wire harness. At room temperature (around 70°F/21°C), the sensor should read approximately 10,000 ohms (10kΩ). If it reads “OL” (Open Loop) or 0 (Short), the sensor is dead. If it reads something wild like 80k, it’s drifted and needs to go.

4. Accessing the Main Board (If Sensor Tests Good): If the sensor tests fine, the break is in the wiring. You’ll need to unscrew the metal panel on the back of the fridge to access the main PCB (Printed Circuit Board). Inspect the “CON” connectors for any signs of scorching or loose pins. Use your needle-nose pliers to ensure the pins are seated firmly.

5. Replacement and Reassembly: If the sensor failed the Ohm test, plug in your new OEM replacement part. Ensure the connector “clicks” into place—a loose connection will bring the error code right back in a week. Snap the plastic cover back on and secure the screw. Don’t over-tighten; it’s just plastic.

6. The Reset Procedure: Plug the unit back in. The error might stay on the screen for a minute while the board runs its Self-Test. If it doesn’t clear, press and hold the “Energy Saver” and “Lighting” buttons (or “Freezer” and “Ref” depending on your model) simultaneously for 5-10 seconds to force a logic reset.

Technical Explanation of the Fault

In my twenty years of turning wrenches on these machines, I’ve found that “Er rt” failures usually boil down to one of three technical breakdowns. Here is the deep dive into why your Kenmore is throwing a tantrum:

• Thermistor Resistance Drift: The RT sensor is an NTC (Negative Temperature Coefficient) thermistor. Its electrical resistance changes based on the temperature. Over years of exposure to humidity and heat cycles, the internal chemicals in the sensor degrade. This “drift” means the sensor might report a resistance level that translates to -40°F or 150°F—values the control board knows are impossible, triggering the error.
• Wiring Harness Degradation: The sensor is often located near the top hinge or the rear of the unit. The wires connecting it to the main control board are thin (22-24 gauge). Vibration from the compressor or even a small amount of corrosion at the terminal connector can increase resistance or create an “open loop,” effectively cutting the sensor off from the “brain.”
• Voltage Spikes & Logic Failure: Sometimes the sensor is fine, but the “pull-up resistor” on the main control board has been fried by a power surge. If the board can’t interpret the incoming voltage from the sensor, it defaults to the Er rt code as a safety measure to prevent the compressor from burning out.

How to Prevent Error Er rt

Once you’ve got it fixed, you don’t want to be doing this again in six months. First, **install a high-quality appliance surge protector**. Refrigerator control boards are incredibly sensitive to “dirty power” and voltage spikes that occur during thunderstorms or grid switching. A $30 protector can save a $200 board.

Second, **maintain proper airflow**. If your refrigerator is crammed into a tight cabinetry space with no clearance at the top, the ambient heat builds up. This “micro-climate” forces the RT sensor to operate at its thermal limits constantly, which accelerates the chemical degradation of the thermistor. Keep at least an inch of clearance on all sides to ensure the sensor is reading actual room air, not trapped heat.

Frequently Asked Questions

Can I run the refrigerator while the Er rt code is active?
Technically, yes, but it’s a gamble. The unit will often enter a “timed-run” mode, meaning it cycles the compressor based on a fixed timer rather than actual temperature needs. This can lead to spoiled food or a frozen evaporator coil. Fix it as soon as possible.

Why did my Kenmore show this after a power outage?
Power outages are often preceded by voltage sags or followed by spikes. This can “glitch” the control board’s memory or physically damage the sensor’s resistance properties. Always try a “hard reset” (unplugging for 10 minutes) before buying parts.

Is Kenmore the only brand with this error?
No. Kenmore is often manufactured by LG or Whirlpool. If your Kenmore starts with model number “795,” it’s an LG-built unit, and the “Er rt” is a very common occurrence in their design due to the sensor’s placement near the top hinge.