Lennox Mini-Split Error Codes and What They Might Mean

October 8, 2021
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Lennox mini-split systems are a solid way to provide compact, yet effective temperature control for your home. Some models are built for air conditioning only, while heat pump models can offer both heating and cooling.

But no piece of HVAC equipment is flawless. There’s always a possibility your mini-split can malfunction. To find out what went wrong, you should locate where the mini split error codes are displayed. Knowing what these codes refer to can help ensure fast mini-split repair, especially if professional help is necessary.

What any code means will ultimately rely on the specific model of your mini-split system. You can consult your manual for a guide for what each code means. You can also trust the HVAC pros at Winters Heating and Cooling. Our technicians are trained to learn these codes in order to ensure prompt mini split repair in Franklin & South Indy. Give us a call at 317-406-5382 to book an appointment.

Common Lennox Mini Split Error Codes

While error codes will differ from model to model, there are some codes you’ll be more likely to see. To learn what your error code may mean, consider the following:

  • Is your system a mini-split air conditioner or a mini-split heat pump?
  • Are there other signs of what malfunctioned? A strange noise comes from an important component, for example.

Here are some of the more common error codes for Lennox mini-splits.

E1 – Indoor / Outdoor Unit Communication

In general, an E1 error code signifies that communication between the mini-split system’s indoor and outdoor units has been hampered. It may be facing intermittent connection problems or have failed entirely. When the indoor and outdoor units can’t communicate with one another, they will not be able to effectively balance indoor temperatures.

E5 – Voltage Protection or Temperature Sensor Error

If you own a mini-split heat pump, an E5 error may stand for a problem with the system’s voltage. A repair technician from Winters Heating and Cooling may refer to it as overcurrent protection. Both excessively high or low voltage can create this error code.

For mini-split air conditioners, this code may also indicate voltage issues. In other cases, it’s pointing you to a circuit problem with the outdoor temperature sensor.

E6 – Indoor / Outdoor Unit Communication

An E6 error code can also refer to a communication problem between the two units, similar to an E1 code. It might also be an issue with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will generally be related to your mini-splits compressor system, housed within the outdoor unit. When the compressor drive is not working, the most likely reason is excessively high temperatures. A high temperature at the discharge line may also lead to a P4 code.

P6 – Compressor Switch Open or Drive Board Failure

Your mini-split system will have computer boards that ensure the indoor and outdoor units can communicate with one another. If the drive board is damaged, a P6 error code is common.

When temperatures rise above safe levels, a safety switch will protect the electrical components of your mini-split system, including any components that manage the outdoor compressor. If this switch is open, the P6 code may appear. You may also find the P6 code if the compressor is facing high or low-pressure issues.

Review the Manual for Your Specific Model

Remember that in general, error codes are specific to each model of a Lennox mini-split system. Your manual will offer a guide for these error codes and what they can mean. But since many of these codes start with electrical problems, professional experience is typically required.

Call Winters Heating and Cooling for Mini Split Repair

Winters Heating and Cooling can offer fast and affordable ductless mini split repair. Whether you own a mini-split AC system or a mini-split heat pump, our technicians can quickly identify your unique problem.

For some problems, repairs may not be worth it. But that doesn’t mean the mini-split replacement process has to be stressful. We can provide equally effective mini split installation in Franklin & South Indy, bringing your new system online with little to no comfort disruption.

To schedule an appointment, give us a call at 317-406-5382 today.