Aircon condenser dripping water: when it is normal
Daikin says that during cooling, the pipes in the outdoor unit become cold and may cause condensation, so condensed water can drip from the outdoor unit. This is Daikin's explanation for its own units, on its air conditioner troubleshooting page. For another brand, follow your own model's manual or ask the maker.
That does not make every drip fine. From a high-rise flat, the water can land on a neighbour's window, a ledge below or the wall.
Have the unit and its drainage checked when:
- water keeps dripping with the aircon switched off
- water pools on the ledge instead of draining away
- drips fall on the flat below or on hanging laundry
- stains spread down the outside wall
Where the water should go
In an HDB flat, the water has a set route. HDB's home care guide for air-conditioners asks you to inspect your aircon regularly: there should be no leaking, and the condensate piping should run into the flat to a floor trap. HDB's renovation guidelines for air-conditioner installation works add that all aircon piping must run internally and that condensate must discharge into a floor trap in the flat.
The same HDB guidelines place the upkeep on the flat owner. Owners must keep the external wall free from stains at their own expense, maintain the aircon regularly to avoid inconvenience or nuisance to neighbours, and attend to any nuisance when it arises. Otherwise, HDB will ask them to stop using or remove the condensing unit.
So condenser water running down the wall or onto the flat below is something to fix, not something to live with. Our guide to aircon installation rules for HDB flats covers the wider rules.
If you live in a condo or landed home, ask your installer or technician where the condensate pipe drains.
Trays and mosquitoes
A tray under the outdoor unit can look like a quick fix for drips. The National Environment Agency (NEA) advises against it: trays or receptacles should not be placed beneath or on top of any aircon unit. If a tray is needed for other issues, NEA says to install HDB's patented aircon tray and still check it for chokes at the drainage point (NEA preventive measures). Instead, look at the drainage: HDB's installation guidelines say condensate must discharge into a floor trap in the flat.
For other spots where water collects at home, such as pails and plant pot plates, see how to prevent mosquito breeding.
Check it yourself
These checks help you tell a normal drip from an outdoor aircon unit leaking where it should not.
- Watch when it drips. From a window, without leaning out, note whether it drips only while the aircon is cooling.
- Follow the condensate pipe. Inside the flat, trace the pipe to the floor trap. While it cools, check that water comes out and the end is not choked.
- Look at the wall. From a window or the ground, check the wall below the ledge for stains.
- Ask the flat below. Check with your neighbour whether water lands on their window or laundry.
For water dripping inside from the indoor unit, see aircon leaking water. Daikin says to stop using the aircon, collect the water in a bucket or with a floor cloth, and check whether water comes out of the drain hose outside (Daikin).
What a technician 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 |
In the directory, 21 companies publish an aircon repair or inspection line. 11 of them price it per job, from S$40 to S$100 per job as printed, with S$43.60 per job in the middle: one company's own published rate, not an average.
The remaining lines are priced per visit or per unit, such as an aircon diagnosis fee of S$27.25 per visit and a checking line of S$35 per unit. Some visit fees are printed as waived if the repair goes ahead, and one line says the fix is quoted separately, so ask what the visit covers.
If you also want the outdoor unit cleaned, compare published rates for condenser cleaning.
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
Call an aircon technician if you notice any of these:
- Heavy dripping or pooling. Water runs off the unit steadily or collects on the ledge.
- Drips on a neighbour's window or laundry. HDB says owners must attend to any nuisance to neighbours (HDB installation guidelines).
- The unit also stops or makes noise. See our guide to a noisy aircon condenser.
- Rusty brackets. HDB says stainless steel brackets should be free of corrosion and rust, and to check with your aircon serviceman whether a corroded or rusty unit needs replacing (HDB home care guide).
Before you book, compare aircon servicing prices or browse aircon companies and their published rates.
Questions
Should water drip from the outdoor unit when the aircon is off?
If it drips while the aircon is off, have it checked. Daikin explains outdoor unit drips as condensation from pipes that become cold during cooling (Daikin), and that explanation covers the cooling period only. A technician can check the unit and its drainage.
Can I put a tray under the outdoor unit?
Not an ordinary tray. NEA says trays or receptacles should not be placed beneath or on top of any aircon unit; if one is needed for other issues, install HDB's patented aircon tray and check it for chokes at the drainage point (NEA). HDB expects condensate to discharge into a floor trap in the flat (HDB).
My neighbour's condenser drips on my window. What can I do?
Talk to your neighbour calmly first, and if that does not settle it, try mediation. HDB says owners must maintain their aircon to avoid nuisance to neighbours and attend to any nuisance when it arises, or HDB will ask them to stop using or remove the condensing unit (HDB). Show them where the water lands.
Does a dripping outdoor unit mean low gas?
Not necessarily. Daikin explains water dripping from the outdoor unit as condensation on pipes that become cold during cooling (Daikin). If you think the gas may be low, ask a technician to check rather than guessing. One company in the directory prints a gas troubleshooting line at S$87.20 per job.
Who cleans stains on the wall below my aircon ledge?
The flat owner is responsible. HDB says owners must keep the external wall free from stains at their own expense (HDB). If you rent, tell the owner when you notice stains. Have the drainage checked at the same time.
Can I go onto the aircon ledge to check?
No. Never climb or lean out onto the ledge. HDB says the aircon ledge is only for the condensing unit (HDB installation guidelines) and warns that an improperly installed or maintained aircon can fall and cause serious injury or death to people below (HDB home care guide). Leave outside work to your technician.
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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