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

But no home comfort system is flawless. There’s always a possibility your mini-split could malfunction. To determine what went wrong, you should 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 needed.

What the error 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 contact the HVAC pros at PS Cool Heat. Our technicians are trained to learn these codes in order to provide prompt mini-split repair in Highlands Ranch. Give us a call at 720-613-2210 to schedule an appointment.

Common Lennox Mini-Split Error Codes

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 may mean, ask yourself the following:

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

Are there additional signs of what malfunctioned? A loud noise coming from a key 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 signifies that communication between the mini-split system’s indoor and outdoor units has been hampered. It could be struggling with 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 PS Cool Heat may refer to it as overcurrent protection. Both unusually 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 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 might also be an issue with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will most times be related to your mini-splits compressor system, located 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 may also trigger 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 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 could appear. You may also find the P6 code if the compressor is struggling with high or low pressure concerns.

Check Your Service Manual for Specifics

Don’t forget that in general, error codes are different for 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 usually required.

Call PS Cool Heat for Mini-Split Repair

PS Cool Heat 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 identify your specific 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 Highlands Ranch, bringing your new system online with little to no comfort disruption.

To schedule an appointment, give us a call at 720-613-2210 today.