Water dripping onto parquet: algae blocking the drain tray
Water dripped from the front of the wall unit onto the bedroom floor. A drip like this looks like a cracked drain tray and a major repair. But a front drip usually means the tray is overflowing rather than split, so the question was what blocked the outlet.
By Team Snowflake | Updated 28 Jul 2026
Case summary
Samsung Wall-mounted9 years oldHDBNovena, Singapore
- Concern
- Worried about water damage to the parquet flooring below the unit.
- Found
- Drain tray choked with algae and biofilm blocking the drain outlet, causing drain water to overflow the tray and drip from the front of the unit
- Key check
- Removed the front panel and inspected the drain tray surface and outlet before testing the drain line
- Result
- The drip stopped immediately once the tray was cleaned and the drain outlet cleared. The unit resumed normal operation with its original drain tray still in place. We dried the parquet floor and found no lasting damage to it.
What we were told
Water had been dripping from the front of the wall unit onto the parquet floor in the master bedroom. Towels under the unit were not keeping up, and the drip was getting worse. The worry was a cracked drain tray, and a unit needing major disassembly or replacement. The flooring below was the bigger concern.
What we checked
A front drip on a wall unit points to the drain tray overflowing, not a pipe leak at the back. A cracked tray would leak from behind instead. We removed the front panel to inspect the tray surface and the outlet first, before testing the drain line.
The drain tray had a thick layer of green algae and biofilm. It covered the whole tray surface and sat over the drain outlet, sealing it shut.
Drain water was pooling in the tray with no path to the drain line. It spilled over the front edge, which matched exactly where the drip appeared inside the room.
After cleaning the tray and clearing the outlet, water drained freely into the drain line. That confirmed the blockage, not a crack, was the cause.
We inspected the tray surface once it was clean. No cracks, holes, or corrosion were found, so the tray was sound and did not need replacing.
What we found
Algae and biofilm had built up in the drain tray over several years. The layer slowly covered the drain outlet until water could no longer flow out. Drain water then backed up and overflowed from the front of the unit. The tray itself stayed structurally intact.
What fixed it
The drain tray was not cracked. The drip came from algae blocking the drain outlet. We cleaned the tray, cleared the biofilm from the outlet, and flushed the drain line to confirm flow. No parts were needed, so the fix stayed simple and low-cost.
Outcome
The drip stopped immediately once the tray was cleaned and the drain outlet cleared. The unit resumed normal operation with its original drain tray still in place. We dried the parquet floor and found no lasting damage to it.
What this case teaches us
A front drip points to a blocked tray, not a broken one
- Where the water falls is the first clue. A drip from the front means the drain tray is overflowing inside the unit, not leaking from the back.
- Algae and biofilm build up slowly over the years. Given enough time, they cover the drain outlet and block the flow of water out of the tray.
- A blocked tray needs cleaning, not replacing. We check the surface for cracks only after the tray is clean and the outlet is clear again.
Questions this case answers
Water dripping from the front of a wall aircon onto the floor: what does that mean?
Can algae really block an aircon drain?
How do I know the tray is blocked and not cracked?
Will a dripping aircon damage parquet flooring?
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