Older Bukit Merah block leaked after wash: pump discharge tube crimped
A flat in an older Bukit Merah block stayed dry for years, then leaked days after a chemical wash. Five decades of building stock line this port-adjacent corridor. A pump discharge tube crimped during reassembly is easy to miss until the drip actually starts.
By Team Snowflake | Reviewed 11 Jul 2026
Case summary
Sharp Wall-mounted15 years oldHDBBukit Merah, Singapore
- Concern
- The homeowner worried the drain pump had already failed, only days after paying for a full chemical wash.
- Found
- Drain pump discharge tube left crimped at the bend exiting the pump casing after the wash, restricting normal flow
- Key check
- Checked the discharge tube's routing and crimp point before assuming the pump itself had failed
- Result
- The flat has stayed completely dry since the discharge tube was re-routed properly a few weeks ago. The homeowner avoided paying for pump replacement that the actual fault never required in the first place.
What we were told
The homeowner said the flat had never leaked before and started dripping near the indoor unit about four days after a chemical wash. The drip was slow but steady, always from the same spot. Nothing else in the flat had changed around that time.
What we checked
We treated the timing right after the wash as the strongest lead rather than assuming the pump itself had failed outright. A genuine pump failure usually shows other signs, such as unusual noise or a burning smell, neither of which was present here at all. We checked the discharge tube's routing first, before anything else.
The drain pump itself ran normally throughout and cleared water at its expected rate when tested directly.
The pump's discharge tube had been reassembled with a tight crimp at the bend where it exits the pump casing.
Water was backing up at that crimp rather than clearing through the discharge tube properly.
No other part of the drainage path showed any blockage, sludge, or damage of any kind at all.
What we found
During reassembly after the wash, the pump's discharge tube was routed back through a tight bend as it left the pump casing, leaving it crimped at that point. A crimped tube still lets some water through, so it made no obvious difference under light condensate load. But under a normal, heavier load, the restriction was enough to back water up faster than the pump could clear it, and it began overflowing near the indoor unit. This made the pump itself look like the actual point of failure, rather than the tube feeding it.
What fixed it
We re-routed the discharge tube so it left the pump casing without a tight crimp and confirmed free flow at normal condensate load. We did not recommend replacing the pump, since it was working correctly and reliably throughout the visit. We advised checking the discharge tube's routing specifically at every future wash, not just the pump's function, since it is easy to disturb during reassembly.
Outcome
The flat has stayed completely dry since the discharge tube was re-routed properly a few weeks ago. The homeowner avoided paying for pump replacement that the actual fault never required in the first place.
What this case teaches us
A leak right after a wash often means a crimped drain tube, not the pump itself
- A leak that starts within days of a wash is more likely a reassembly gap than a new pump failure.
- A drain tube crimped at its bend during reassembly can restrict flow enough to back water up.
- Ask whether the drain tube's routing was checked for a crimp before any pump replacement is quoted after a wash.
Related reading
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