How many condenses do you have? Is one a multi head? Does the fault occur when all the heads from the multi head are turned on or only when one is turned off? If one is running, does the other heads coil get cold while off? No? Turn the on and the other off If possible send a pic of the piping coming out of the condenser Answer from Nerfixion on reddit.com
Reddit
reddit.com › r/hvacadvice › uh and a5 error code daikin minisplits
r/hvacadvice on Reddit: UH and A5 error code daikin minisplits
June 24, 2023 -
Bought a new house (~750 sq ft) with daikin minisplits, one downstairs (FTXS18LVJU) and two upstairs (CTXS07LVJU). Was having issues with them randomly shutting off and throwing UH error code and one daikin being 10x colder than others. daikin sent out a contractor (which is bs btw, do they not have dedicated techs that just inspect?) and he said the tubing was wrong and it was a $3000 fix. thought it was fishy, had a 2nd hvac guy come out and he said heat pump (4MXS36RMVJU) had low refrigerant and filled it back up. now all blow fairly cold, but if i turn off one of the daikins, then they still go into error mode UH after ~30 mins. any thoughts?
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How many condenses do you have? Is one a multi head? Does the fault occur when all the heads from the multi head are turned on or only when one is turned off? If one is running, does the other heads coil get cold while off? No? Turn the on and the other off If possible send a pic of the piping coming out of the condenser
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What you have is a Daikin Multiport. The problem is likely that the installing contractor mixed up the wiring from the outdoor to the indoor units. Daikin Multiports come with a fix from the factory for this as it’s a common issue. Turn off all indoor units from the remote controllers or thermostats. Remove cover above where the copper line sets leave the outdoor unit by way of two Phillips head screws. You will see a circuit board to the left with several LED lights (4-5 lights). Turn off power to outdoor unit by way of the breaker or the disconnect. Cycle power back on and wait for 5 minutes. Press and release the SW3 button located on the board to the left being very careful not to touch any of the wiring labeled A, B, C, etc. as these wires will have 208-230V active on them. This has initiated the wrong wiring check. If the check has been initiated you will see a flashing pattern of red lights on the board on the left. The test will then run for 10-20 minutes at which time the outdoor unit will shut off. If there were any inconsistencies in the wrong scheme from the outdoor to any or all of the indoor units, then the outdoor unit will automatically correct the wiring internally through the board logic and no physical change will be needed of the wiring scheme. What is basically happening when the wires from A, B, etc. do not correspond correctly to the Port A, Port B, etc. is that the refrigerant goes to an air handler that the blower is not currently running on or is running on low-low, so that the indoor unit begins to freeze up and an A5 error code is given. As you’ve said, the problem doesn’t happen when all indoor units are running as it doesn’t matter at that point that the refrigerant is going to wrong indoor unit as refrigerant is going to all indoor units and all indoor blowers are running. For years this has been the very first thing I do when I come upon a Daikin multiport as I’ve no idea who has been there before me, or if the installer did it correctly or not. It should be noted also that this change is stored in the PCB on the outdoor unit. So in the future if the outdoor unit circuit board is ever replaced or if the entire outdoor unit replaced, the wrong wiring check will need to be done again or else you’re back in the same boat as before.
Daikin
my.daikin.eu › content › dam › DASW › supportavdelningen › Felkoder_SM-TS3errorcode_chart.pdf pdf
Simple Self-Diagnosis by Malfunction Code After Sales Service Division (SM-TS3)
Simple Self-Diagnosis by Malfunction Code · After Sales Service Division
hvac - Multi-split Daikin air-conditioner errors and temperature issues - Home Improvement Stack Exchange
I have two indoor Daikin Perfera FTXM-R units hooked to a 2MXM-N9 outdoor unit. What I noticed is that the indoor unit closer to the outdoor unit (A) will start to report a very low temperature if ... More on diy.stackexchange.com
Daikin AC Units split- Errors UH and A5
A5 is a coil over or under temp depending on the mode. UH means another unit on that system has an A5. A C4 is a thermistor failure. You probably had a thermistor failure that reported a bad coil temp, triggering the A5 and UH. It’s a pretty easy replacement. More on reddit.com
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March 19, 2024UH and A5 error code daikin minisplits
How many condenses do you have? Is one a multi head? Does the fault occur when all the heads from the multi head are turned on or only when one is turned off? If one is running, does the other heads coil get cold while off? No? Turn the on and the other off If possible send a pic of the piping coming out of the condenser More on reddit.com
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June 24, 2023Daikin error code U0 - 00 on a 4 months old system
Yes so that indicates high suction pipe temperature, which is most likely low refrigerant, but could be other things, like a compressor failing to start or a clogged txv. I would advise touch nothing and call out the installers asap ! More on reddit.com
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HVAC-Talk
hvac-talk.com › home › forums › ask our pros-owner assistance - no diy advice › aop residential hvac/refrigeration(beenthere zone)
Daikin A5 and UH errors - wiring issue? | HVAC-Talk: Heating, Air & Refrigeration Discussion
July 9, 2024 - Just ran a test 08:10 Lower ground ... ground floor, A5 error on lower ground ... I notice in the Daikin app that it says "Operation conflict"....
Daikin
daikin.com › products › ac › services › error_codes
Error Codes | After Sales Service | Air Conditioning and Refrigeration | Daikin Global
Error Code Search offers information on the cause of the malfunction and the status of your air conditioner by entering the error code. Error Code Search List of Error Codes(0.1MB) Please refer to "How to Check Error Codes" for step-by-step instruction to check the error codes.
JustAnswer
justanswer.com › hvac › mpcbg-installed-zone-daikin-mini-split-system-month.html
Daikin Mini Split A5 & UH Error Fix: Expert Q&A Guide
August 9, 2023 - UH errors indicate outdoor unit overheating—check for blocked condenser coils, dirty filters, or low refrigerant levels. Regularly clean filters every 3 months and verify proper airflow.
Facebook
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What could be causing a Daikin ductless 3 zone mini split ...
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CoolAutomation
coolautomation.com › blog › daikin error codes: comprehensive breakdown
Daikin Error Codes: Comprehensive Breakdown
July 20, 2025 - Following are some of the most common Daikin error codes and their presumed causes. Tired of wasting time with repeated on-site visits, finally diagnosing a problem, and then realizing you lack the necessary parts?
Star-supply
star-supply.com › content › Daikin-Troubleshooting Codes.pdf pdf
Trouble Shooting www.climatecenter.co.uk Daikin Trouble Shooting Guide
Capacity setting error · Incorrect capacity setting · • · • · Trouble Shooting · www.climatecenter.co.uk · Daikin Trouble Shooting Guide · Past & Current Models · Daikin Fault Codes · System Fault Codes · Fault Code · Definition · Supposed Causes ·
Stack Exchange
diy.stackexchange.com › questions › 274258 › multi-split-daikin-air-conditioner-errors-and-temperature-issues
hvac - Multi-split Daikin air-conditioner errors and temperature issues - Home Improvement Stack Exchange
June 15, 2023 - On top of this if running both units or just B for a few hours, I get A5 error (freeze-up protection trigger) on the A unit and UH error on the B unit (meaning another unit has failed: unit A).
Lioncityaircon
lioncityaircon.sg › home › home improvement › daikin aircon error codes explained (full list + fix guide 2026)
Daikin Aircon Error Codes Explained
August 23, 2024 - The outdoor PCB’s capacity setting adapter is missing, improper, or the PCB is defective. Installer or technician error. U codes are some of the most common Daikin errors customers ask us about.
Reddit
reddit.com › r/hvacadvice › daikin ac units split- errors uh and a5
r/hvacadvice on Reddit: Daikin AC Units split- Errors UH and A5
March 19, 2024 -
Hey, I have a dual split system with one outdoor condenser unit (2MXS18PMVM) connected to two indoor evaporator units (CTXSO9PMVM5), installed in separate rooms. One of the indoor units started displaying the error code "UH". The other unit is showing an error code "A5". I can't turn on neither of them. Currently there's quite the heatwave where I live, so something might have overheated.
My immediate attention is on the unit showing the "UH" error, as it's where I sleep (the other one is in an empty guest room). If I were to temporarily turn off the unit showing the "A5" error (which I read it might be a problem on the indoor heat exchange of that unit), would it allow the other unit (with the "UH" error, which afaik is a communication/transmission error) to turn on? I'm hoping to at least get the ac on my room running properly until I can get professional help. I'm wondering if anyone has insights into what might be causing these errors or how to fix the one in my room until I'm able to schedule technicians to come look at it
EDIT: After turning on and off all of my apartment circuit breakers, I could the on in my room on, even though it doesn't refrigerate, just ventilate... And the other one is showing that it has the "C4" error
Valley Air Conditioning
valleyairconditioning.com.au › home › daikin air conditioner error codes
Daikin Air Conditioner Error Codes and Troubleshooting
January 22, 2026 - The list below features all the malfunction error codes for Daikin air conditioners and their potential causes.
Controlsdirect
controlsdirect.com.au › daikin-fault-codes
Daikin Fault Codes – ControlsDirect
156 UH Improper connection of transmission wiring between outdoor and outdoor unit outside control adaptor ... 160 UF Failure to carrey out check operation Indoor-outdoor, outdoor-outdoor communication error, etc. ... These Daikin Error Codes or Daikin Fault Codes, are useful to help resolve ...
Glow HCE
glowhce.com.au › home › daikin fault codes – system errors
Daikin System Error Codes | Simple Self Diagnosis | Daikin Fault Codes
October 13, 2023 - Daikin System Fault Codes - Simple self-diagnosis by malfunction codes. Is your Daikin air conditioner system displaying an error code starting with U? See here
LinkedIn
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Mark C. McQuay's Post
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JustAnswer
justanswer.com › hvac › es5qo-daikin-vrv-system-one-indoor-units.html
Daikin VRV System Q&A: Troubleshooting Indoor Units and Error Codes
I have a Daikin split system with multiple indoor units. One unit has a flashing LED and error code U4.
Silverback Air-con
silverbackaircon.sg › home › aircon error code › daikin error code › daikin a5 error code and how to fix it
Daikin A5 Error Code and How To Fix It - Silverback Air-con
February 23, 2024 - The Daikin A5 error code typically signals that the air going inside the air conditioner is way colder than the regulated temperature. It can be caused by an aircon valve problem, which is very expensive to fix, a faulty indoor thermistor, evaporator coil, or compressor.
Airintelligence
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Perthaircon
perthaircon.com.au › home › daikin error and fault codes
Daikin Error and Fault Codes – Daikin Air Conditioning Perth by Airpro Air Conditioning
How to identify what is required with your Daikin Aircon via the self diagnosis error code.
Quora
quora.com › How-do-you-fix-the-Daikin-UF-error-code
How to fix the Daikin UF error code - Quora
Answer: If your Daikin air conditioner is displaying the UF error code, this means that the unit has detected an abnormality in the operation of the outdoor fan. This is a serious error code and should be addressed as soon as possible. There are a few things that you can do to try and fix the UF...