Daikin aircon error code: what it tells you
An error code is how the unit reports what it has detected. Daikin says checking the error code identifies the status and the issue of the air conditioner, and its Error Code Search gives the cause of a malfunction for a code you enter. These are Daikin's global pages, so check what you read against your own model's manual too.
HomezyPro has no link with Daikin. This page uses Daikin's published pages only, and the code descriptions below are in Daikin's own words. Some codes point to something you can check yourself, such as the air filters. Most point to a part that a technician should inspect and repair.
How to read the code on the remote
Seeing a Daikin aircon blinking is how many people first notice a fault: on many units, a flashing operation lamp is the first sign. Our aircon blinking light guide has more on what a flashing lamp can mean.
To see the code itself, use the remote. Daikin publishes a How to Check Error Codes guide with steps for each remote controller type. The steps differ by remote, so follow the guide for your remote and your model's manual.
- Note what you see. Write down what the operation lamp or display shows.
- Read the code. Find your remote controller type in Daikin's How to Check Error Codes guide and follow its steps.
- Look it up. Enter the code in Daikin's Error Code Search, or check your model's manual.
- Note the code before you call. Write down the code and your model before you call anyone.
Common codes and their causes
The codes below come from Daikin's self-diagnosis table, its Simple Self-Diagnosis by Malfunction Code list, in Daikin's own descriptions. The list covers several Daikin ranges, so a code can mean something different on another range or another brand.
| Code | Daikin's description | What you can do |
|---|---|---|
| A1 | Malfunction of indoor unit PCB | Call a technician |
| A3 | Drain level control system abnormality; causes listed include drain clogging and a defective drain pump | Call a technician |
| A5 | Freeze-up protection control in cooling; causes listed include a clogged air filter of the indoor unit | Clean the filters, then call a technician if it returns |
| A6 | Malfunction of fan motor | Call a technician |
| U0 | Shortage of refrigerant | Call a technician |
| U2 | Malfunction of power supply or instantaneous power failure | Call a technician if it returns |
| U4 | Malfunction of transmission between indoor and outdoor unit | Call a technician |
Daikin's self-diagnosis table describes a Daikin error code U4 as a malfunction of transmission between the indoor and outdoor unit. That is a job for a technician, as is every fix on this list beyond cleaning the filters.
A5 is the one code here with a check you can do yourself. Daikin recommends cleaning the air filters every 2 weeks, with water or a vacuum cleaner, and says that when the operation lamp flashes you can clean the filters and restart. Daikin also says not to use a commercial cleaning spray inside the aircon, as it may damage internal components. Our guide on how to clean an aircon filter walks through the steps.
Codes that need a technician
If the operation lamp still flashes after you clean the filters, Daikin's troubleshooting page gives these steps: turn off the aircon, switch off its circuit breaker and wait twenty minutes, turn the breaker back on, then turn the aircon on and check the operation light. Do this once only. If the problem remains, Daikin says to contact your nearest Daikin representative.
U0, a shortage of refrigerant in Daikin's self-diagnosis table, is never a DIY job: a technician should find the cause before any top-up. Our guide to aircon gas top-up cost has more on top-ups.
If water leaks from the indoor unit, Daikin says to stop using the aircon, collect the water and check whether water comes out of the drain hose outside, removing anything blocking its end. If none drains out, Daikin says to contact the installer or Daikin to request a service. Our Daikin aircon servicing guide covers routine care.
What a check or repair visit costs
FROM THE HOMEZYPRO DIRECTORY
Published aircon repair and inspection rates
For the most common unit (per job), the lowest published rates from 11 companies run from S$40 to S$100. Each figure is one company's own advertised rate with its conditions, not a market average or a quote.
See 21 published repair or inspection rates and sources
| Company | Service as listed | Rate | Source |
|---|---|---|---|
| Skyzone Aircon Pte Ltd | Aircon diagnosis fee (residential) | S$27.25 per visit | skyzone.com.sg |
| Snowflake Services LLP | Diagnostic visit (waived if you proceed) | S$30 per visit | snowflakeaircon.sg |
| City Cooling Pte Ltd | Checking | S$35 per unit | citycoolingengr.com.sg |
| A-Max Aircon | Troubleshooting | S$40 per job | amaxaircon.com |
| Blossom Engineering & Construction Pte. Ltd. | Troubleshooting | S$40 per job | blossomaircon.com |
| Coolest Aircon Service Pte Ltd | Aircon Repair | S$40 per visit | coolestaircon.com.sg |
| Doctor Cool | Aircon repair or troubleshooting | S$40 per job | doctorcoolsg.com |
| SmartCool Aircon Servicing Singapore | Troubleshooting | S$40 to S$80 per job | smartcool.sg |
| Thetop Aircon Service | Aircon troubleshooting repair | From S$40 per job | thetop.com.sg |
| Goodcool | Aircon Troubleshooting | S$43.60 per job | bestairconservicing.com |
| Aircon Boon | Ttroubleshooting [sic] | S$50 per job | airconsg88.com |
| Sky Blue Aircon Engineering Pte. Ltd. | Troubleshooting & diagnostics visit (from; waived upon repair) | From S$50 per visit | skyblueaircon.com |
| Jiaxing Holdings Pte. Ltd. | Onsite inspection checking fee (waived if the repair proceeds within 1 month) | S$54.50 per visit | jiaxing-aircon.sg |
| Heng Aircon Pte Ltd | Diagnostic check | S$60 per visit | hengaircon.com |
| Same Day Aircon Servicing Repair | Repair troubleshooting (fix quoted separately) | From S$60 to S$80 per job | urgentairconservicing.sg |
| Vois Pte. Ltd. | Aircon troubleshooting | From S$60 per unit | vois.com.sg |
| Airple | Aircon Troubleshooting | S$60.60 per job | airple.com.sg |
| Lion City Air Conditioner Services | Gas troubleshooting | S$87.20 per job | lioncityaircon.sg |
| Joydom Engineering Pte. Ltd. | On-site troubleshooting visit | S$100 per job | joydom.com.sg |
| Cool-Aire Aircon Servicing | VRF Troubleshooting - On site survey / Transport charges | S$150 per visit | coolaire.com.sg |
| Homeone Aircon | Compressor replacement labour, split (<3hp), parts excluded | S$600 per unit | homeone.com.sg |
These are independent companies' published troubleshooting and repair visit rates in the directory, quoted as printed, not Daikin's own service rates. In all, 21 companies publish a repair or inspection line. Of these, 11 price it per job, from S$40 to S$100 per job, with S$43.60 per job as the middle company's own published rate, not an average. Other lines are priced per visit or per unit, such as S$27.25 per visit or S$35 per unit, and some say the fee is waived if the repair goes ahead, so ask. More on our aircon repair page.
NEXT STEP
See aircon companies in the directory with their published prices, the areas they say they cover and their sources.
Compare aircon companiesWhen to stop and call a professional
- The code comes back after the restart steps.
- A burning smell or abnormal noise from the indoor unit: Daikin says to stop operation, turn off the breaker if everything is dry and contact the place of purchase.
- Water leaking from the indoor unit near sockets, plugs or wiring: keep away and call a Licensed Electrician.
- A U0 code or a PCB code such as A1.
Compare aircon servicing prices or browse aircon companies.
Questions
Can I clear a Daikin error code by switching the aircon off?
Sometimes, once. For a flashing operation lamp, Daikin's steps are to turn off the aircon, switch off its circuit breaker and wait twenty minutes, then turn the breaker and the aircon back on. Only do this when everything is dry. If the code comes back, do not keep restarting the unit: call a technician.
Does an error code mean the aircon is broken?
Not always. In Daikin's self-diagnosis table, the causes listed for A5 include a clogged air filter of the indoor unit, so cleaning the filters comes first. Other codes, such as a fan motor or PCB malfunction or a shortage of refrigerant, need a technician.
Do other aircon brands use the same codes?
No. Codes differ by brand, and a code can mean different things on different ranges from the same maker. Use your own brand's manual or support page, and ask the maker if the code is not listed.
What can I check myself before calling a technician?
Only what you can see and reach, never anything inside the unit. Clean the air filters, which Daikin recommends every 2 weeks, and check that the drain hose outside is not bent or blocked at its end. Then use Daikin's breaker restart once, only when everything is dry. If the code returns, call a technician.
Should I get a gas top-up when the aircon shows U0?
Not before the cause is found. U0 means a shortage of refrigerant in Daikin's self-diagnosis table, and a technician needs to check for a leak before any top-up. Ask the technician what they found and how they plan to fix it before you agree to a top-up.
Can any aircon company repair a Daikin unit?
Independent companies service and repair many brands. When you book, give the code and your model, ask what they found and which parts they plan to use, and agree the price before work starts.
Prices come only from the sourced company rates in the HomezyPro directory, shown with each company and its source.
Practical guidance for planning a home job in Singapore. Company prices come from the HomezyPro directory, each linked to its source; rules and safety points link to the agency or manufacturer that sets them. This is not a site inspection, a quote or professional advice for your home.
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