Lennox mini-split systems are an excellent way to provide compact, yet effective 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 will malfunction. To determine what happened, 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 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 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 schedule 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 determine what your error code could mean, consider the following:

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

Are there clear signs of what is happening? A loud noise coming from a key 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 indicates that communication between the mini-split system’s indoor and outdoor units has been disrupted. It could be experiencing intermittent connection issues 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 may indicate 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 produce 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, similar to an E1 code. It may 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, 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 could 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 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

Don’t forget 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 can mean. But because many of these codes refer to electrical problems, professional experience is usually necessary.

Contact 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.