Lennox Mini Split Error Codes and What They Could Mean

October 25, 2021

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

But no ductless mini split is flawless. There’s always a risk your mini split can malfunction. To determine what went wrong, you’ll want to 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 the error code means will ultimately rely on the specific model of your mini split system. You can review your manual for a guide for what each code means. You can also call the HVAC pros at B & B Heating & Cooling. Our technicians are trained to recognize these codes in order to provide prompt mini split repair in Florissant. Give us a call at 314-325-7552 to schedule an appointment.

Common Lennox Mini Split Error Codes

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

  • Is your system a mini split air conditioner or a mini split heat pump?
  • Are there other signs of what is happening? A loud noise coming from a key component, for example.

Here are a few of the more common error codes for Lennox mini splits.

E1 – Indoor / Outdoor Unit Communication

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

E5 – Voltage Protection or Temperature Sensor Error

If you own a mini split heat pump, an E5 error may indicate a problem with the system’s voltage. A repair technician from B & B Heating & Cooling may refer to it as overcurrent protection. Both unusually high or low voltage can result in this error code.

For mini split air conditioners, this code can also stand for 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, like an E1 code. It may also be an issue with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will usually be concerned with 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 could also trigger a P4 code.

P6 – Compressor Switch Open or Drive Board Failure

Your mini split system will have computer boards that make sure the indoor and outdoor units can communicate with one another. If the drive board is faulty, 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 can appear. You may also find the P6 code if the compressor is facing high or low pressure concerns.

Consult the Manual for Your Specific Model

Don’t forget 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 should mean. But as many of these codes stem from electrical problems, professional experience is often required.

Call B & B Heating & Cooling for Mini Split Repair

B & B Heating & 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 diagnose your unique problem.

For some problems, repairs might 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 Florissant, bringing your new system online with minimal comfort disruption.

To schedule an appointment, give us a call at 314-325-7552 today.