Landed unit drips after rain: leaf sludge in the drain tray
A Seletar landed unit started dripping after several wet evenings. The room still cooled, so the first question was whether rain and green-fringe debris had affected the drain path before anyone quoted a cracked tray or indoor replacement.
By Team Snowflake | Reviewed 15 Jun 2026
Case summary
Daikin Wall-mounted6 years oldLandedSeletar, Singapore
- Concern
- Owner thought the tray had cracked because water appeared only after wet weather.
- Found
- Leaf sludge blocking the drain tray outlet
- Key check
- Opened the cover and checked the tray outlet before quoting tray replacement
- Result
- The dripping stopped during the test run and did not require parts. The owner had a simple rule for future reports: note whether the leak follows rain, long runtime, or both. That pattern helps decide whether to start with drainage, insulation, or a broader indoor inspection.
What we were told
The living-room unit cooled normally, but water appeared along the lower casing after rainy evenings. The owner had wiped the filter and could not see a crack. The drip stopped for a while, then returned the next wet week.
What we checked
Because cooling was still normal, we did not start with gas or major indoor parts. We checked the water path first: tray condition, tray outlet, drain hose fall, and whether debris had collected near the outlet. The weather pattern mattered because Seletar homes near green roads can collect fine organic material around drain and coil areas.
The drain tray was intact and did not show a crack.
The tray outlet had dark leaf sludge gathered around the opening.
Water backed up when the unit ran longer after rain.
The drain hose still had fall, so the blockage was at the tray side.
What we found
Fine leaf matter and slime had collected at the tray outlet. The unit could drain during short runs, but after wet evenings the moisture load rose and the partial blockage became enough to overflow the tray. The fault looked like a failed tray from the outside because water came from the casing edge, but the tray itself was not broken. The issue was the first narrow point in the drain path.
What fixed it
We cleared the tray outlet, flushed the drain path, and checked that water left steadily before closing the unit. We also advised the owner to watch the pattern after heavy rain, not only after long cooling sessions. No tray replacement was quoted because the leak stopped once the blocked outlet was cleared. The next maintenance should include a drain-path check, not just filter washing.
Outcome
The dripping stopped during the test run and did not require parts. The owner had a simple rule for future reports: note whether the leak follows rain, long runtime, or both. That pattern helps decide whether to start with drainage, insulation, or a broader indoor inspection.
What this case teaches us
Rain timing can point to the drain path
- A leak that appears after wet weather is not automatically a cracked tray. Debris and slime can move into the tray outlet when humidity and rain load rise.
- Open the cover and check the tray outlet before approving bigger work. A clean front filter does not prove the drain path is clear.
- In green-fringe homes, outdoor debris and indoor drain condition should be checked together when water returns after rain.
Related reading
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