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 piece of HVAC equipment is flawless. There’s always a chance your mini-split can malfunction. To determine what happened, you’ll want to locate where the mini-split error codes are displayed. Recognizing what these codes mean can help you kick-start mini-split repair, especially if professional help is required.

What the error code means will ultimately rely on the specific model of your mini-split system. You can check your manual for a guide for what each code means. You can also trust the HVAC pros at Ilten's. Our technicians are trained to learn these codes in order to ensure prompt mini-split repair in Cedar Rapids. Give us a call at 319-208-2351 to book an appointment.

What Error Codes for Lennox Mini Splits Are Most Common?

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

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

Are there other signs of what malfunctioned? A loud noise coming from a specific 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 experiencing intermittent connection problems or have failed entirely. When the indoor and outdoor units can’t communicate with one another, it will be unable to properly balance indoor temperatures.

E5 – Voltage Protection or Temperature Sensor Error

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

For mini-split air conditioners, this code may also represent 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 may also be an issue with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will most times 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 result in 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 could appear. You may also find the P6 code if the compressor is experiencing high or low pressure issues.

Consult the 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 have a guide for these error codes and what they should mean. But because many of these codes refer to electrical problems, professional experience is typically required.

Call Ilten's for Mini-Split Repair

Ilten's can deliver 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 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 Cedar Rapids, bringing your new system online with minimal comfort disruption.

To schedule an appointment, give us a call at 319-208-2351 today.