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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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See What Our Customers Are Saying:

by iqster in Toronto on Twintech Heating and Cooling

Received a new range and needed someone to disconnect the old range and connect the new gas range. They did a thorough job and were kind enough to remove the old range from the house. Thank you!

by AJM in Pickering on Twintech Heating and Cooling

Very satisfied with this company! Salesperson Dave was very good, very knowledgeable and gave me the impression that he wanted to sell me what I needed rather than what would put the most money in the company's pocket. He also called back after the installation to see if I was satisfied with the result. The installation crew of Greg, Grant and Peter did a great job. They arrived on time, completed the job quickly, answered all my questions and thoroughly cleaned up. They told me to call if I had any further questions. They left me with the impression that they really cared about their work and my satisfaction and that it wasn't " just a job". Prior to researching for a new furnace, I had never heard of this company but I'm glad that I did and would highly recommend them to anyone looking for a new furnace or air conditioning unit. They may be small but they do a great job!!

by David from Toronto on Twintech Heating and Cooling

I first met Greg and Grant (The Twin Brothers from Twin Tech - yup -it's not just a cool company name) back in 2014 when our furnace broke down and they installed our Carrier Furnace and AC that we purchased through Sears. I liked them instantly when I met them due to their friendly and professional service, and the fact that they didn't mind taking a little extra time to explain things in terms I could understand. Since that time they have reached out to me at least once a year to ensure that everything was running smoothly with my system and to keep me appraised of their evolving services. Due to this high level of proactive customer service I didn't hesitate to call and obtain their help for a Gas Stove removal and installation. When I scheduled the call Greg and Grant let me know that they would arrive the morning of the appliance delivery to disconnect the old gas stove, and then return in the afternoon to connect the new stove. Sure enough, they did just that as promised. Where they exceeded my expectations is with the extra level of support helping to assemble the burners and grills on the stove and in the oven. This may seem like a small thing to some but to my wife who was at home during this entire process it meant a stress free transition to the meal prep for the day. When I called home to ask about the install she commented that, "they left the place cleaner than it was when they arrived and they setup all the grills on top of the stove and in the oven... they didn't have to do all that -Wow!". You know what they say, Happy Wife, Happy Life. So in summary, I am recommending Twintech Heating & Cooling for all of your Furnace, Air Conditioning, and Gas Line needs. I've even called on these guys to help swap out a leaky water valve. They are just so easy to reach and communicate with by phone, and they don't mind a text message to confirm the details. You can rest easy when you have the Twins on your side as an extension of your household maintenance plan.

by Jr in Pickering on Twintech Heating and Cooling

First thing, they actually showed up for a quote. Other big name companies in the area didn't even return my call , job was done as expected and new equipment is quiet and installed very clean and professional. Would highly recommend these guys.

by Melissa P. from Port Hope on Twintech Heating and Cooling

They removed our old furnace and replaced it with a new furnace and AC system.

by Nancy H. from Oshawa on Twintech Heating and Cooling

Work was performed in a clean and timely manner. The furnace and metal work was performed by the Twintech team (did not require separate contractor to do the metal work). Energy audit was arranged and promised rebates were received. The overall price was very competitive. We have recommended Twintech to several of our friends and family. Awesome job.

by Syd from Whitby on Twintech Heating and Cooling

Grant and Greg installed a heating and AC system in our new Linwood post and beam home. Post and beam can be challenging structures for running ductwork and their high ceilings and open concept frequently frustrate efforts at balancing air flow and controlling temperatures. But these guys did it and did it right the first time. Even the building inspector was impressed with what he saw. More importantly, the boys brought a high degree of trust and integrity to the job. Something in short supply these days.

by jenner iksmom from Oshawa on Twintech Heating and Cooling

Very polite and professional. They removed my o
ld furnace and A/C and installed my new ones. They were efficient and thoroughly cleaned up when they were done! I would highly recommend them!

by Rob from Toronto on Twintech Heating and Cooling

Pro from start to finish. They were able to fix my gas fireplace at very little cost as well.

by murray mcmichael from Ajax on Twintech Heating and Cooling

Excellent installation very knowledgeable gentlemen! Would highly recommend them to all my friends for any hvac work !

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See What Our Customers Are Saying:

by Aaron on Twintech Heating and Cooling

We are very happy to recommend this company to everyone. Our furnace broke down on Sunday morning. We phoned them and before noon Grant the owner showed up. He worked on the furnace for about a hour not wanting to give up to fix the problem. The furnace was 17 years old. I was the one talking about replacing it. End result was the next day it was all done. On the Sunday Bob came over with heaters to warm up the house. We decided to replace the water heater at the same time. Thanks Grant for the excellent work. Thumbs up.

by Linda on Twintech Heating and Cooling

Right on time. Explained how to work the HRV in a different way so the house would not be so dry. Changed my whole house water filter for me as well. Friendly, helpful, caring service!

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.

by Robert Mizuno on Twintech Heating and Cooling

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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