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 home comfort system is flawless. There’s always a chance your mini-split could malfunction. To identify what happened, you should locate where the mini-split error codes are displayed. Recognizing what these codes refer to can help ensure fast mini-split repair, especially if professional help is needed.

What any 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 trust the HVAC pros at Contra Costa Heating & AC. Our technicians are trained to learn these codes in order to ensure prompt mini-split repair in The Bay Area. Give us a call at 510-343-9841 to request 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 come across. To determine 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 additional signs of what is happening? 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 means that communication between the mini-split system’s indoor and outdoor units has been disrupted. 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 effectively balance indoor temperatures.

E5 – Voltage Protection or Temperature Sensor Error

If you own a mini-split heat pump, an E5 error could refer to a problem with the system’s voltage. A repair technician from Contra Costa Heating & AC 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 can 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 could also be a problem with one of the temperature sensors.

P4 – Compressor Drive Error / High Temperature

A P4 error code will generally be connected to your mini-splits compressor system, found within the outdoor unit. When the compressor drive is not working, the most likely culprit is excessively high temperatures. A high temperature at the discharge line can 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 issues.

Check the Manual for Your Specific Model

Don’t forget that in general, error codes are specific to each model of a Lennox mini-split system. Your manual will offer a guide for these error codes and what they can mean. But since many of these codes refer to electrical problems, professional experience is typically necessary.

Call Contra Costa Heating & AC for Mini-Split Repair

Contra Costa Heating & AC 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 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 little to no comfort disruption.

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