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What Do AC Error Codes Mean?

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What Do AC Error Codes Mean?

Posted On: June 2, 2024

What Do AC Error Codes Mean?

Air conditioning (AC) units can display error codes when something goes wrong. These codes are specific to the manufacturer and model of the AC unit, but here are some general explanations for common AC error codes:


General AC Error Codes

  1. E1/E2/E3/E4: These codes often indicate issues with sensors:


    • E1: Room temperature sensor error.
    • E2: Indoor coil sensor error.
    • E3: Indoor fan speed malfunction.
    • E4: Outdoor coil sensor error.
  2. F1/F2/F3: These codes are usually related to the frequency drive or the main control board.


    • F1: Indoor unit PCB (Printed Circuit Board) error.
    • F2: Outdoor unit PCB error.
    • F3: Outdoor ambient temperature sensor error.
  3. H1/H2/H3: These codes generally indicate protection errors.


    • H1: Defrosting mode.
    • H2: Overload protection of the compressor.
    • H3: High-temperature protection of the compressor.
  4. P1/P2/P3: These codes typically relate to pressure or system malfunctions.


    • P1: High pressure protection of the system.
    • P2: Low pressure protection of the system.
    • P3: Protection against lack of refrigerant or malfunction in the refrigerant system.
  5. L1/L2/L3: These codes can be related to electrical issues.


    • L1: Phase loss or imbalance.
    • L2: Overcurrent protection.
    • L3: Voltage error or under-voltage protection.

Manufacturer-Specific Error Codes

LG

  • CH 01: Indoor unit room temperature sensor error.
  • CH 02: Indoor unit pipe temperature sensor error.
  • CH 03: Communication error between indoor and outdoor units.

Daikin

  • U0: Low refrigerant.
  • U4: Transmission error.
  • E1: Circuit board malfunction.

Mitsubishi

  • P1: Abnormal rise in pressure.
  • P8: Outdoor unit air temperature sensor error.
  • E0: Inverter/compressor malfunction.

Samsung

  • E101: Communication error.
  • E121: Indoor temperature sensor error.
  • E154: Outdoor coil sensor error.

What to Do When an Error Code Appears

  1. Consult the Manual: The best source of information is the user manual or service manual for your specific AC model.
  2. Reset the Unit: Sometimes, resetting the unit by turning it off and on again can clear the error.
  3. Check for Obvious Issues: Ensure that filters are clean, vents are not blocked, and that there is no visible damage to the unit.
  4. Call a Professional: If the error persists, it's best to contact a professional technician. They can diagnose and fix the issue safely.

Understanding these codes can help you determine whether the issue is something simple that you can fix yourself or if you need to call a professional for assistance.



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by Private User on Twintech Heating and Cooling

Twintech promptly responded to request for quotation. They were thorough and helpful in explaining options. The quote was very competitive. Installation of new furnace was very professionally completed. Excellent work.

by Rita, Scarborough on Twintech Heating and Cooling

When our old oil furnace finally broke down we decided it was time to finally convert to natural gas and finally install central air conditioning at the same time. Knowing it was going to be a significant investment for us, we wanted to make the right choice. Twintech came highly recommended by a friend and we were not disappointed. From the first contact with the salesperson, until the final touches on the installation, we were so pleased with their service. Everyone from the company was so friendly, efficient and a pleasure to deal with. Best of all, the cost was very competitive. We would certainly recommend Twintech to anyone requiring HVAC work in their home.

by Bob S, Pickering on Twintech Heating and Cooling

Mitch from Twintech came out for our annual furnace inspection. We found him to be friendly, conscientious & he left the work area clean. We were also very impressed with the thoroughness of the job he did. This is the 2nd job we’ve had Twintech do for us & have been very happy with the results for each. We highly recommend this company. Thank you, Mitch, Dave & Greg.

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Work was done on schedule, professionally, according to quote and with minimal inconvenience to building users. Very happy with the end result. The only area for improvement from my experience - need more timely quoting process.

by Karen on Twintech Heating and Cooling

The team was great! Very knowledgeable, professional and extremely helpful. A few days after install the unit didn’t seem to be working, user error, but within minutes of contacting them..on a Saturday.. a tech was on the phone troubleshooting with us. I highly recommend Twintech for your cooling or heating needs. They stand by their products and a pleasure to deal with.

by Rob on Twintech Heating and Cooling

During the hottest week in the summer our old A/C decided to call it quits. I called Twintech Heating & Cooling after receiving a referral from a family member; came highly rated for being an honest, family-run business, who appreciates their customers. Dave was able to accommodate my hectic schedule and book a late evening appointment to walk through the specifics. Greg and Mitch arrived exactly on time a few days later, were very polite and friendly, and within a couple of hours had a new unit up and running. I also received a follow-up call to ensure we were happy with the Amana.

by Linda Robinson on Twintech Heating and Cooling

They were on time and very professional. I'm so glad I decided to go with Twintech, thanks!

by Famcam1953 on Twintech Heating and Cooling

Timely and appreciated - this was during the hottest days this year when our Air and Furnace way.
Efficient. Professional. No BS or overselling. What was promised, was delivered at a cost-effective price point.
Down to earth.

by DG Sellers on Twintech Heating and Cooling

Professionally done and took care to cover all entry floors to the house for the installers to remove the old furnace and install a new furnace.
I also made recommendations of the tankless water heater that we had installed and items to address. We did not know they also installed tankless water heaters.

by Bill, Pickering on Twintech Heating and Cooling

Price was not the cheapest nor the most expensive of my quotes. It's the quality of the installation that makes for a good AC system. The twins' knowledge & professionalism was evident in the small details:
Very clean work. Greg made sure that the refrigerant level & temperature were correct. They reinstall the insulation & vapor barrier around the wall. The outside electrical cords were secured to the wall. Proud to support this local company. Thank you.

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by Robert Rogers on Twintech Heating and Cooling

Very pleased with the professional service that TwinTech Heating and Cooling provided in replacing my furnace. I got several quotes from different service providers. Their price was excellent and they explained the features very well. We are very glad we went with TwinTech and highly recommend their services.

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We were new homeowners in need of a second opinion. TwinTech Heating & Cooling were Amazing and professional. Very knowledgeable and great service all around. Recommend to anyone looking for honest and reliable services. Treated with respect and care. Thank you Greg, Mitch and Bob!

by Ruth on Twintech Heating and Cooling

TwinTech is an excellent and honest company! I called them for a second opinion after being told by another company that I needed to replace my furnace. Turns out this was not the case at all! I did not need a new furnace. TwinTech did not push to make an unnecessary sale and saved me from a huge expense. Bob and Mitch were extremely professional and above all honest! I definitely recommend TwinTech!

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Amazing experience with TwinTech Heating & Cooling! Their team was professional, knowledgeable, and efficient from start to finish. They installed my new furnace quickly and left everything spotless. The technicians took the time to explain everything and made sure I was comfortable with the system before they left. Great customer service and fair pricing. I highly recommend them for anyone needing HVAC services!

by Connor Agnew on Twintech Heating and Cooling

Great experience all around. Bob was sharp and easy to talk to, and Greg handled the installation perfectly. Would hire them again in a heartbeat.

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