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 piece of HVAC equipment is flawless. There’s always a possibility your mini-split can malfunction. To determine 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 required.

What each code means will ultimately rely on the specific model of your mini-split system. You can review your manual for a guide for what each code means. You can also call the HVAC pros at May's Heating & Air. Our technicians are trained to recognize these codes in order to provide prompt mini-split repair in Frederick. Give us a call at 301-690-0397 to book an appointment.

What Error Codes for Lennox Mini Splits Are Most Common?

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

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

Are there other 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 signifies that communication between the mini-split system’s indoor and outdoor units has been disrupted. It may be struggling with 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 can 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 create this error code.

For mini-split air conditioners, this code could also indicate 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, like 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 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 may also result in 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 damaged, 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 manage the outdoor compressor. If this switch is open, the P6 code may appear. You may also find the P6 code if the compressor is facing high or low pressure concerns.

Review the Manual for Your Specific Model

Remember 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 as many of these codes stem from electrical problems, professional experience is often required.

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 minimal comfort disruption.

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