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 will malfunction. To identify what is malfunctioning, you should locate where the mini-split error codes are displayed. Understanding what these codes refer to can help you kick-start mini-split repair, especially if professional help is needed.

What any 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 call the HVAC pros at Retro HVAC Service & Installation. Our technicians are trained to recognize these codes in order to ensure prompt mini-split repair in Philadelphia. Give us a call at 267-277-3851 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 encounter. 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 loud noise coming from a key component, for example.

Here are a handful 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 experiencing intermittent connection problems or have failed entirely. When the indoor and outdoor units can’t communicate with one another, it will not be able to properly balance indoor temperatures.

E5 – Voltage Protection or Temperature Sensor Error

If you own a mini-split heat pump, an E5 error can stand for a problem with the system’s voltage. A repair technician from Retro HVAC Service & Installation 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 can also represent 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 an issue 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, housed within the outdoor unit. When the compressor drive is malfunctioning, the most likely reason is excessively high temperatures. A high temperature at the discharge line may also trigger 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 malfunctioning, 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 control the outdoor compressor. If this switch is open, the P6 code may appear. You may also find the P6 code if the compressor is experiencing high or low pressure concerns.

Check the Service Manual for Specifics

Keep in mind that in general, error codes are specific to each model of a Lennox mini-split system. Your manual will provide a guide for these error codes and what they should mean. But because many of these codes stem from electrical problems, professional experience is typically necessary.

Trust Retro HVAC Service & Installation for Mini-Split Repair

Retro HVAC Service & Installation can provide 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 Philadelphia, bringing your new system online with minimal comfort disruption.

To schedule an appointment, give us a call at 267-277-3851 today.