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 offer both heating and cooling.

But no home comfort system is flawless. There’s always a risk your mini-split will malfunction. To determine what happened, you should locate where the mini-split error codes are displayed. Understanding what these codes mean can help ensure fast 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 consult your manual for a guide for what each code means. You can also call the HVAC pros at Contra Costa Heating & AC. Our technicians are trained to learn these codes in order to provide prompt mini-split repair in The Bay Area. Give us a call at 510-343-9841 to book an appointment.

What Error Codes for Lennox Mini Splits Are Most Common?

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 may mean, consider the following:

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

Are there other signs of what is happening? A loud noise coming from a specific 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 disrupted. It might be struggling with 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 effectively 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 Contra Costa Heating & AC may refer to it as overcurrent protection. Both unusually high or low voltage can produce this error code.

For mini-split air conditioners, this code could also stand for 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, found within the outdoor unit. When the compressor drive is malfunctioning, the most likely cause is excessively high temperatures. A high temperature at the discharge line can also lead to 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 exceed 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 can appear. You may also find the P6 code if the compressor is facing high or low pressure issues.

Review Your Manual for Specifics

Remember 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 since many of these codes stem from electrical problems, professional experience is typically needed.

Call Contra Costa Heating & AC for Mini-Split Repair

Contra Costa Heating & AC 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 specific 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 The Bay Area, bringing your new system online with minimal comfort disruption.

To schedule an appointment, give us a call at 510-343-9841 today.