Complete Guide To Common Mini Split AC Error Codes AND How To Fix

 Complete Guide To Common Mini Split AC Error Codes AND How To Fix

Error codes are useful since they let us know something isn’t right with the mini split system. Still, they’re also concerning if we aren’t sure what they mean or how to deal with it. In this article, we’ll look at the complete guide to common mini split error codes and what to do with each one. First, let’s talk about what a mini split system is.

Mini Split Systems

Mini split systems allow you to control the temperature in individual rooms. Unlike a central air system that involves ductwork, mini splits use no ductwork and are hooked up in the rooms that need temperature control.

They work with two units: one outdoor compressor and an indoor handling unit. Mini splits are an excellent solution for smaller spaces, individual areas and rooms, and if there is a desire to avoid ductwork.

What Are Error Codes?

Error codes are installed in a mini split system to alert the homeowner that something has gone wrong. Each error code represents an issue, and once you learn the codes, it’s easy to quickly assess the situation. Sometimes, a system seems to be running fine, and still, an error code pops up. Don’t ignore it. It’s a warning that if the error isn’t taken care of, the system may fail.

Six Different Error Codes

1. EO – communication fault (indoor/outdoor)
2. EC – outdoor communication fault
3. E1 – sensor for room temperature
4. E2 – coil temperature sensor (indoor)
5. E3 – coil temperature sensor (outdoor)
6. E4 – abnormal system
7. E5 – wrong model configuration
8. E6 – indoor fan motor
9. E7 – outdoor sensor for temperature
10. E8 – temperature sensor for exhaust
11. E9 – module and drive fault/intelligent power
12. EF – fan motor module (outdoor)
13. EA – current sensor fault
14. EE – EEPROM
15. EP – temperature switch fault
16. EU – sensor fault (voltage)
17. EH – intake temperature sensor
18. P1 – protection from over or undervoltage
19. P2 – protection from overcurrent
20. P4 – exhaust overtemperature protection
21. P5 – subcooling
22. P6 – overheating protection (cooling mode)
23. P7 – overheating protection (heating mode)
24. P8 – protection for overtemperature and under temperature (outdoor)
25. P9 – software control (drive protection)
26. P0 – hardware control (module protection)

The list is long, and it’s helpful to keep it near the mini split system so you can check error codes when necessary.

Troubleshooting Error Codes

Even if you memorize all 26 error codes, you’ll still need to know what to do when one makes its presence known. The first thing you want to do is figure out how to make the error code go away. This won’t fix the problem, but it’s the first step in clearing everything and getting the mini split to run efficiently again.

To clear the error code, turn the unit off, then turn off the breaker. Fix the issue and turn the unit back on. If you aren’t ready to fix the problem, you can turn the unit back on anyway, after a few minutes, and see if the error code goes away. If the problem is still there, the code will come back.

After clearing the code, whether it’s a professional or yourself, it’s time to check for the three most common reasons for error codes to show up. Although there are 26 codes, they can all stem from one of the following reasons:

1. Problem with the wiring.
2. A faulty sensor
3. A faulty PCB

To troubleshoot the wiring and sensors, simply check all wiring connections and sensors to see if there’s a malfunction. Another possibility is the computer board (PCB) is not reading the correct voltage from the sensors. That causes an error code as well.

Here’s a list of the possible sensors to check:

1. Indoor room temperature (T1)
2. Evaporator temperature (T2)
3. Condenser temperature (T3)
4. Outdoor ambient temperature (T4)
5. Compressor discharge temperature (T5)

To check a sensor, use the manual the system came with to locate the sensor you need to check. Look at the sensor and the wiring for any possible shorts or breaks. Also, check for resistance. Unfortunately, sometimes a unit was wired wrong from the beginning, and after some time goes by, the error codes begin to alert.

If all sensors and wiring seem fine, this usually points to the PCB, and it may need replacing. Unfortunately, many of these repairs are not suitable for DIY. Call your technician right away to get your mini split system running efficiently and safely.

Perform Regular Maintenance

Schedule regular maintenance with your HVAC professional twice a year. This is often done in the spring to prepare for summer, then again in the fall to prepare for the colder months. An HVAC technician will do the following at a mini split system checkup:

• Clean filters and replace if necessary.
• Clear out any debris or obstacles in the way of the outdoor unit.
• Check all valves and tighten or replace when needed.
• Clean the coils.
• Check for leaks of refrigerant.

You can help maintain your system between visits by keeping debris, overgrown landscaping, and snow away from the outdoor unit. Check filters occasionally when the unit has been working hard. Keep an eye out for wiring, tubing, or valves that don’t look right. Be aware of odd smells coming from the unit, both indoors and out.

Don’t ignore odd sounds, either. Contact your HVAC professional if your senses notice anything unusual. And of course, if the temperature isn’t responding as it should, schedule a visit with your technician.

👉Mini split systems are the perfect solution for the following types of areas:

• Smaller homes that don’t need a large central unit.
• Single rooms that aren’t heated or cooled efficiently.
• New additions without ductwork.
• New builds when the owner is choosing no ductwork.