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

But no ductless mini-split is flawless. There’s always a risk your mini-split will malfunction. To identify what went wrong, you’ll want to locate where the mini-split error codes are displayed. Understanding what these codes mean can help you kick-start mini-split repair, especially if professional help is needed.

What the error code means will ultimately depend 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 contact the HVAC pros at May's Heating & Air. Our technicians are trained to learn these codes in order to deliver prompt mini-split repair in Frederick. Give us a call at 301-690-0397 to book an appointment.

Common Error Codes for Lennox Mini Splits

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

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

Are there additional signs of what is happening? A loud noise coming from an important 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 means that communication between the mini-split system’s indoor and outdoor units has been disrupted. It could be facing intermittent connection issues 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 may indicate a problem with the system’s voltage. A repair technician from May's Heating & Air may refer to it as overcurrent protection. Both very high or low voltage can result in 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, like 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 most times be connected to your mini-splits compressor system, located within the outdoor unit. When the compressor drive is faulty, 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 faulty, a P6 error code is common.

When temperatures rise above 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 could appear. You may also find the P6 code if the compressor is experiencing high or low pressure concerns.

Review the Manual for the Exact Model

Remember that in general, error codes are different for each model of a Lennox mini-split system. Your manual will have a guide for these error codes and what they can mean. But because many of these codes refer to electrical problems, professional experience is often necessary.

Call May's Heating & Air for Mini-Split Repair

May's Heating & Air 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 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 Frederick, bringing your new system online with little to no comfort disruption.

To schedule an appointment, give us a call at 301-690-0397 today.