Lennox mini-split systems are a great 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 ductless mini-split is flawless. There’s always a chance your mini-split can malfunction. To find out what is malfunctioning, you’ll want to locate where the mini-split error codes are displayed. Knowing what these codes mean can help you kick-start 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 consult your manual for a guide for what each code means. You can also contact the HVAC pros at Morgner Inc. Air Conditioning & Heating. Our technicians are trained to recognize these codes in order to deliver prompt mini-split repair in Saint Louis. Give us a call at 314-262-4541 to book 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 see. To identify what your error code could mean, ask yourself the following:

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

Are there clear signs of what malfunctioned? 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 means that communication between the mini-split system’s indoor and outdoor units has been impeded. It could be experiencing intermittent connection issues 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 could refer to a problem with the system’s voltage. A repair technician from Morgner Inc. Air Conditioning & Heating may refer to it as overcurrent protection. Both very high or low voltage can create this error code.

For mini-split air conditioners, this code can 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 could also be a problem with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will generally be connected to your mini-splits compressor system, found within the outdoor unit. When the compressor drive is not working, the most likely cause is excessively high temperatures. A high temperature at the discharge line can also lead to 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 exceed 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 the Exact Model

Keep in mind 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 because many of these codes refer to electrical problems, professional experience is often needed.

Contact Morgner Inc. Air Conditioning & Heating for Mini-Split Repair

Morgner Inc. Air Conditioning & Heating 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 specific 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 Saint Louis, bringing your new system online with little to no comfort disruption.

To schedule an appointment, give us a call at 314-262-4541 today.