Lennox SL22KLV Heat Pump Error Code 108: Faulty Temperature Sensors (Indoor/Outdoor)

If your Lennox heat pump model SL22KLV is flashing error code 108, you’re likely dealing with faulty temperature sensors, either indoor or outdoor. This disrupts the system’s ability to regulate indoor temperature, potentially leading to increased energy bills and discomfort.

To get your system up and running, you’ll need to identify and troubleshoot the issue – and we’re about to walk you through exactly how to do that.

Understanding Lennox Heat Pump Error Code 108

When your Lennox heat pump displays error code 108, this is a signal that the system has detected a refrigerant leak.

This error code is often related to faulty temperature sensors, which can affect the indoor/outdoor temperature control.

As a result, your HVAC system may not function efficiently, and you may need to ponder heat pump repair.

This is crucial to address this issue promptly to avoid further damage to your outdoor units.

Lennox Mini Splits, in particular, require precise temperature control to operate effectively.

Also, Read: Lennox SL22KLV Heat Pump Error Code 107: Compressor Protection Mode Activated

Causes of Faulty Temperature Sensors

Because temperature sensors play a critical role in maintaining ideal indoor/outdoor temperature control, faulty sensors can trigger Lennox heat pump error code 108.

You may wonder what causes these sensors to malfunction.

Common causes include high temperature at the discharge, communication problem, and compressor drive error.

Additionally, a protection or temperature sensor malfunction, leading to faulty temperature sensors.

Also, Read: Lennox SL22KLV Heat Pump Error Code 106: Defrost Sensor Failure Detected

Identifying Indoor and Outdoor Temperature Sensors

When troubleshooting Lennox heat pump Error Code 108, you’ll need to identify the indoor and outdoor temperature sensors.

The location of these sensors is vital, as incorrect readings can trigger the error code.

You’ll want to look for symptoms like inconsistent heating or cooling, and then follow troubleshooting steps to isolate the faulty sensor.

Sensor Location Importance

The Lennox heat pump’s accurate operation relies heavily on correctly installed temperature sensors.

You must guarantee that these sensors are located to provide accurate temperature readings can lead to fault error code 108, indicating faulty temperature sensors.

• Indoor temperature sensor: located near the indoor unit, from direct sunlight and heat sources
• Outdoor temperature sensor: typically installed outside, protected from direct sunlight and weather conditions
• Sensor proximity to the Lennox heat pump model SL22KLV’s outdoor unit: guarantee correct sensor placement for accurate readings
• Clearance from obstacles: maintain a safe distance to prevent interference with sensor readings

Sensor Failure Symptoms

Faulty temperature sensors trigger Lennox heat pump error code, and identifying the symptoms is crucial to troubleshooting.

When your HVAC system’s indoor or outdoor sensors fail, you’ll notice abnormal temperature readings. The Lennox heat pump may display incorrect temperature data, causing the system to malfunction or fail to operate efficiently.

You might experience uneven heating or cooling, leading to discomfort and increased energy bills. In some cases, the system may shut down entirely, resulting in a complete loss of heating or cooling.

Sensor Troubleshooting Steps

To pinpoint the faulty temperature sensor, you’ll need to identify the indoor and outdoor sensors in your Lennox heat pump system.

These sensors play a vital role in temperature control, and a faulty one can trigger error code 108.

• Check the indoor temperature sensor, usually located on the Lennox Mini’s Open or Drive Board, for signs of damage or corrosion.
• Verify the voltage supply to the sensor, ensuring it’s within the recommended range to avoid high or low voltage issues that can cause a circuit problem.
• Inspect the discharge line for any blockages that might affect the temperature sensor’s accuracy.

If you’re still unable to identify the faulty sensor, it may be necessary to consult a professional to diagnose the issue, as it could be related to Voltage Protection or Temperature, or even a Compressor Switch Open issue.

Also, Read: Lennox SL22KLV Heat Pump Error Code 105: Low Pressure Detected in Outdoor Unit

Common Issues With Temperature Sensors

When troubleshooting Lennox heat pump error code 108, you’ll likely encounter issues with temperature readings.

Sensor failure, which can be caused by corrosion or physical damage, is a common culprit behind these errors, and you’ll need to identify the malfunctioning sensor type to resolve the issue.

You’ll need to investigate temperature reading errors, including faulty readings or no readings at all, to get your heat pump up and running again.

Sensor Failure Causes

Temperature sensors can malfunction due to environmental factors, leading to Lennox heat pump error code 108.

You might be wondering what causes sensor failure.

As a skilled technician, you should consider the following factors that can contribute to temperature sensor malfunction:

• Moisture or condensation buildup on the sensors, affecting temperature control and communication between indoor and outdoor units.
• Physical damage or wear and tear, leading to faulty sensor readings.
• Poor installation or calibration of the sensors, resulting in inaccurate temperature readings.
• Corrosion or exposure to harsh chemicals, affecting the sensor’s ability to communicate with the heat pump model, such as the Lennox Mini.

Temperature Reading Errors

What’s behind the inaccurate temperature readings that trigger Lennox heat pump error code 108?

You’re dealing with faulty temperature sensors, which can be either indoor or outdoor.

These sensors are responsible for providing accurate temperature readings to your Lennox heat pump’s control system.

When they malfunction, you get incorrect temperature readings, causing your heat pump to malfunction and display error code 108.

Faulty temperature sensors can lead to inefficient heating and cooling, increased energy bills, and even system breakdowns.

It’s vital to address temperature reading errors promptly to prevent further damage to your Lennox heat pump.

Malfunctioning Sensor Types

Faulty temperature sensors can lead to inaccurate readings, and it’s the specific type of sensor malfunctioning that determines the extent of the issue.

As you troubleshoot the Lennox Mini’s error code 108, you’ll want to identify the malfunctioning sensor type:

• Outdoor temperature sensor: A faulty outdoor sensor can prevent the HVAC system from accurately reading the outside temperature, leading to temperature control issues.
• Indoor temperature sensor: A malfunctioning indoor sensor can cause the air conditioning system to malfunction, resulting in inconsistent indoor temperatures.
• Thermistor sensor: A faulty thermistor sensor can disrupt the temperature reading process, causing the system to malfunction.
• Capacitor sensor: A malfunctioning capacitor sensor can lead to inaccurate temperature readings, affecting the overall performance of the HVAC system.

Also, Read: Lennox SL22KLV Heat Pump Error 104: High Pressure Detected in Outdoor Unit

Troubleshooting Steps for Error Code 108

When Lennox heat pump error code 108 appears, you’ll need to identify the root cause to restore system operation.

First, verify the HVAC system is turned off to prevent further damage.

Next, inspect the indoor and outdoor temperature sensors for signs of physical damage, corrosion, or loose connections.

Check the sensor wiring for any signs of wear or fraying.

If you’ve recently replaced the air filter, confirm it’s properly seated to avoid disrupting temperature control.

Follow the troubleshooting steps outlined in your Lennox heat pump’s manual to isolate the faulty sensor.

Replacing Faulty Temperature Sensors

You’ve isolated the faulty temperature sensor, and now it’s time to replace it.

This is a vital step in the error code 108 with your Lennox heat pump.

When replacing the temperature sensors, make sure to:

• Purchase replacement sensors that are compatible with your Lennox heat pump model (SL22KLV).
• Follow the manufacturer’s instructions for installation to avoid any future problems.
• Verify that the new sensors are securely connected to the heat pump unit and the indoor/outdoor units.
• Double-check that the sensors aren’t damaged or faulty during the replacement process, as this can cause the error code to persist.

Also, Read: Lennox SL22KLV Heat Pump Error Code 103: Outdoor Unit Overcurrent Detected

Resetting the Lennox Heat Pump

After replacing the temperature sensors, resetting the Lennox heat pump is crucial to guarantee it operates efficiently and error-free.

You’ll need to reset the system to clear the error code 108, which indicates faulty temperature sensors.

Start by turning off the power to the heat pump at the circuit breaker or fuse box.

Wait for 30 seconds to allow the system to discharge.

Then, check the indoor and outdoor units to verify they’re functioning correctly.

Once you’ve confirmed the system is working, you can rest assured that the repair is complete, and your HVAC system is running smoothly again.

Expert Guidance for Error Code 108

The Lennox heat pump error code 108 diagnosis requires a meticulous approach to guarantee accurate troubleshooting.

As an HVAC technician, you’re likely familiar with the importance of precise diagnostics.

When dealing with error code 108, you’re faced with a temperature sensor issue, which can be tricky to pinpoint.

• Check the indoor and outdoor temperature sensor connections for signs of damage or corrosion.
• Verify that the temperature sensors are installed correctly, ensuring they’re not obstructed or exposed to direct sunlight.
• Use a multimeter to test the sensor resistance and voltage readings.
• If you’re still unsure, it may be necessary to replace the faulty temperature sensor to resolve the error code 108 issue.

Also, Read: Lennox SL22KLV Heat Pump Error Code102: Low Refrigerant Charge Detected

Preventing Future Temperature Sensor Issues

To prevent future temperature sensor issues, it’s essential that you guarantee their proper installation and protection from environmental factors.

Certify the outdoor temperature sensor is installed at a spot that’s representative of the outdoor temperature, and the indoor sensor is installed away from direct sunlight and air vents.

Regularly inspect the sensors for signs of damage or corrosion.

A well-maintained HVAC system reduces the likelihood of fault codes like 108.

Also, Read: Lennox SL22KLV Heat Pump Error Code 101: Loss of Communication Between Outdoor and Indoor Units

Frequently Asked Questions

How to Clear Lennox Error Code?

You’ll need to identify the faulty sensor symptoms, understand heat pump troubleshooting, and know error code meanings to clear the Lennox error code, then check sensor locations, perform sensor cleaning, and consider heat pump maintenance tips to resolve the issue.

How Do I Know if My Lennox Coil Sensor Is Bad?

You’ll know if your coil sensor is bad if you notice faulty sensor symptoms like incorrect temperature readings or system malfunctions. Consult sensor location diagrams, troubleshooting guides, and diagnostic tool reviews to identify and potentially replace the sensor.

How Do I Reset a Lennox Heat Pump?

You reset your heat pump by shutting off breakers, powering back on, and checking for proper winter operation, ensuring filter replacement and thermostat adjustment for ideal energy efficiency, reduction, and faultless defrost mode, before performing a thorough system inspection.

Why Is My Heat Pump Not Reaching the Set Temperature?

As you shiver in the chill, your heat pump’s struggle to reach the set temperature is like a puzzle with many missing pieces: cold air, inconsistent temperatures, incorrect settings, and more, all contributing to a frustrating game of thermal limbo.

Conclusion

You’ve finally resolved the pesky Error Code 108 on your Lennox SL22KLV heat pump! It was a wild ride, with faulty temperature sensors throwing your system into chaos. But now, after identifying and replacing the culprits, your heat pump is humming along smoothly.

Remember, a single malfunctioning sensor can bring your entire system to its knees, so stay vigilant and keep those sensors in check!