They have their own specific setup that I can’t remember (too many schematics in my brain). If it runs for a little bit and then shuts off for a while, kicks on for a bit and yada yada, check your condensate line, might be tripping a “safety switch.” Thats a quick fix, vacuum out the line. Check around the condenser and see if there’s a bunch of droppings. Rodents like to keep warm and chew on wires, those little bastards. Could be a number of things. But I’d start with the condy line. Answer from Deleted User on reddit.com
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reddit.com › r/hvacadvice › [daikin vrv] [220 vac] u4-01 error code help
r/hvacadvice on Reddit: [Daikin VRV] [220 VAC] U4-01 Error Code Help
September 6, 2024 -
My air conditioning failed on me some time today when I was at work, and when I returned home it was 92° inside my home. Figures this would happen during the (hopefully) hottest week of the year in Los Angeles. This system was professionally installed in June of 2020, and has worked without issue until now. The company that did it was bought out by another larger firm, and they are unable to send a tech out for another 17 days. I’m kind of SOL there. I change the filters every six months in the air handlers, and regularly hose down/clean the exterior unit. With a basic visual inspection, it does not appear that there are any blockages/impediments to air flow. I have tried powering off both the exterior unit and both interior air handlers by switching off the breakers on two separate occasions. The cooling works for about 10 minutes and then the error message is displayed again on the interior control panel. Any ideas?
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They have their own specific setup that I can’t remember (too many schematics in my brain). If it runs for a little bit and then shuts off for a while, kicks on for a bit and yada yada, check your condensate line, might be tripping a “safety switch.” Thats a quick fix, vacuum out the line. Check around the condenser and see if there’s a bunch of droppings. Rodents like to keep warm and chew on wires, those little bastards. Could be a number of things. But I’d start with the condy line.
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So the error you're getting is for the loss of communication between the indoor and outdoor unit. Usually you would get this immediately if the communication wire actually has an issue, but since the unit runs and cools for 10 mins that's kind of giving the sign of power loss at the outdoor unit at the 10ish min mark. Sadly I think there is more to your issue than just this error code.
JustAnswer
justanswer.com › hvac › kv8uf-daikin-support-air-con-heater-error-code-u4-01.html
Daikin U4-01 Error Code? Troubleshooting Help & Fix Guide
December 22, 2022 - The U4-01 error on Daikin units typically indicates a temperature sensor or communication fault. First, power off the unit and check sensor wiring connections for looseness or damage. Clean the air filters and ensure no obstructions block airflow.
Daikin U4 Error - Air conditioners
Anyone know anything about a Daikin U4 error in an oldish R407C (RZP71DV1) unit? - We have replaced all four boards and the fan motor in the out door unit- When More on forums.whirlpool.net.au
emergency daikin error U4 - Refrigeration-Engineer.com forums
Hello my friends!!I want your valuable help. I have a daikin RX35JV1NB air condirioning and the problem I face is that the a/c is constantly out of operation and having the indoor green led always flashing.. Regardeless of the times I tried to reset it, the problem remains the same.. More on refrigeration-engineer.com
Daikin U4 error code - Refrigeration-Engineer.com forums
I've been asked to look at a Daikin ducted unit model RYEP71L7V1 in an apartment block. The initial problem was the indoor unit freezing up quite badly and causing considerable leaks in the ceiling void. Plus the remote displaying a U4 error code (comms problem?). My client uses the apartment ... More on refrigeration-engineer.com
[Daikin VRV] [220 VAC] U4-01 Error Code Help
They have their own specific setup that I can’t remember (too many schematics in my brain). If it runs for a little bit and then shuts off for a while, kicks on for a bit and yada yada, check your condensate line, might be tripping a “safety switch.” Thats a quick fix, vacuum out the line. Check around the condenser and see if there’s a bunch of droppings. Rodents like to keep warm and chew on wires, those little bastards. Could be a number of things. But I’d start with the condy line. More on reddit.com
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September 6, 2024Videos
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Star-supply
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Daikin Single-Multi U4 Error Codes
If correct voltage is present on the outside wire, reconnect the wire and turn on the unit. If the U4 error still
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What does Daikin inverter mini split U4 error code mean?
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AirReps
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Understanding the U4 Error Code in Daikin VRV Systems - AirReps
November 19, 2025 - A U4 error code almost always requires professional service. A qualified VRV technician will have the proper tools to test communication signals, measure voltages, and diagnose which component is causing the failure.
Whirlpool
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Daikin U4 Error - Air conditioners
November 25, 2014 - U4 is faulty transmission between the indoor & outdoor units. ... I got the original installer to change the boards, they are qualified but specialize more in new installations than servicing & repairs. When they talked to Daikin account support they seemed to say it's probably the boards/motor ...
HVAC-Talk
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Daikin Minisplit Repair Saga | HVAC-Talk: Heating, Air & Refrigeration Discussion
September 14, 2023 - and removed a water overflow device that we had requested due to overflow incidents with the previous KE unit. Installer also ordered a diagnostic tool from Daikin. 2. A few weeks later we turned the temp. up for heating and it seemed to be okay. Later it started flashing again. Seems to be intermittent. I checked the code and it is the same U4 code as before.
Refrigeration-Engineer.com
refrigeration-engineer.com › forum › refrigeration-divisions › air-conditioning › 32238-emergency-daikin-error-u4
emergency daikin error U4 - Refrigeration-Engineer.com forums
November 24, 2012 - Re: emergency daikin error U4 yep- £230 in uk and £90 for the indoor-carry out the checks that wooleyback mentions to prove it is the a system fault- check the fuses on the outdoor pcb, you have to take the top lid off,remove the plastic lid then to inspect the pcbs theres a few screws to remove , maybe unplug the 4 pin plug for the compressor and unplug the sensor plug, cond fan motor-good luck
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UA & U4 error code Daikin Troubleshoot @highlight
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Daikin India
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Error Codes | Daikin
Customer Support Information: WhatsApp us your query @ 9871409300. Call Our Customer Contact Centre: 011-40319300 / 1860 180 3900 or Write To Us at customerservice@daikinindia.com X
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How to reset error code U4 (VRV4) - YouTube
Brand : Daikin VRV4model : FXMQ63PVE(indoor)/RXQ8AYM(outdoor)error code : U4-01Error code U4System Comunication Fault.This is a communication issue between t...
Published June 26, 2021
Daikin
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Error Code Search Tool - Daikin Philippines
April 21, 2025 - Quickly diagnose Daikin aircon issues with our Error Code Search tool. Find solutions for common problems & troubleshooting steps.
Camper Life
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Daikin Error Code U4-01: Check the Meaning and Easy Fix!
October 16, 2023 - Look for any visible damage to the wires or control board. If there’s damage, repair or replace the affected components to resolve the error code U4-01. When you see the U0 error code on your Daikin air conditioner, it means there’s a problem ...
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DAIKIN VRV ERROR CODE U4 - YouTube
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Published January 18, 2023
PDF Filler
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Daikin U4 01 - Fill Online, Printable, Fillable, Blank | pdfFiller
September 1, 2017 - With the pdfFiller mobile app for Android, you can edit, sign, and share daikin u4 01 form on your mobile device from any location; only an internet connection is needed. Get the app and start to streamline your document workflow from anywhere. Daikin error code U4 typically indicates a communication issue between the indoor and outdoor units of a Daikin air conditioning system.
Toohotclimatesystems
toohotclimatesystems.com.au › troubleshooting-error-codes-for-the-daikin-brc1e63-wall-controller
Troubleshooting Error Codes for the Daikin BRC1E63 wall controller - Too Hot Climate Systems
July 3, 2023 - The Daikin BRC1E63 controller is one of the most popular controllers for the Daikin air conditioning system. It offers advanced control options, a user-friendly interface, and troubleshooting options to fix the errors quickly. However, even the best controllers can encounter errors at times.
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How to Rectify U4 Error Daikin VRV Unit || Daikin VRV U4 ...
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DAIKIN ERROR CODE U 4 SOLUTION ...
Daikin error code U4 indicates a communication error.There are 2 possible causes to this error code. Firstly, the wires between the indoor and outdoor units ...
Published July 19, 2021 Views 22K
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Daikin Mini Split AC Motherboard Fix For U4 Error (Modification) - YouTube
Welcome to our channel, where we dive into the fascinating world of DIY HVAC repairs! In this video, we'll take you through the step-by-step process of repai...
Published July 31, 2023 Views 23K