Lennox mini-split systems are an excellent way to provide compact, yet powerful 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 home comfort system is flawless. There’s always a possibility your mini-split can malfunction. To identify what went wrong, you’ll want to locate where the mini-split error codes are displayed. Recognizing what these codes refer to can help ensure fast mini-split repair, especially if professional help is required.

What each code means will ultimately depend on the specific model of your mini-split system. You can consult your manual to find a guide for what each code means. You can also contact the HVAC pros at Air Alliance Team. Our technicians are trained to learn these codes in order to deliver prompt mini-split repair in Ballwin and St. Charles. Give us a call at 636-206-4584 to schedule an appointment.

Common Error Codes for Lennox Mini Splits

While error codes will differ from model to model, there are some codes you’ll be more likely to come across. To identify what your error code might mean, ask yourself the following:

Is your model a mini-split air conditioner or a mini-split heat pump?

Are there other signs of what is happening? A strange noise coming 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 indicates that communication between the mini-split system’s indoor and outdoor units has been impeded. It could be struggling with intermittent connection issues or have failed entirely. When the indoor and outdoor units can’t communicate with one another, it will be unable to adequately balance indoor temperatures.

E5 – Voltage Protection or Temperature Sensor Error

If you own a mini-split heat pump, an E5 error can refer to a problem with the system’s voltage. A repair technician from Air Alliance Team may refer to it as overcurrent protection. Both unusually 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 alerting 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 a problem with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will usually be related to your mini-splits compressor system, found within the outdoor unit. When the compressor drive is malfunctioning, the most likely culprit is excessively high temperatures. A high temperature at the discharge line can 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 malfunctioning, a P6 error code is common.

When temperatures exceed safe levels, a safety switch should protect the electrical components of your mini-split system, including any components that control the outdoor compressor. If this switch is open, the P6 code can appear. You may also find the P6 code if the compressor is struggling with high or low pressure concerns.

Review Your Manual for Specifics

Don’t forget that in general, error codes are different for each model of a Lennox mini-split system. Your manual will provide a guide for these error codes and what they should mean. But as many of these codes start with electrical problems, professional experience is typically required.

Contact Air Alliance Team for Mini-Split Repair

Air Alliance Team 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 Ballwin and St. Charles, bringing your new system online with little to no comfort disruption.

To schedule an appointment, give us a call at 636-206-4584 today.