Low-rise condo bedroom rattles: trunking cover came loose
A Tanglin low-rise condo bedroom rattled most noticeably at night. The unit still cooled, so we checked nearby trunking and casing vibration before treating the sound as a fan or compressor problem.
By Team Snowflake | Reviewed 15 Jun 2026
Case summary
Fujitsu Wall-mounted9 years oldCondoTanglin, Singapore
- Concern
- Owner worried the indoor fan was failing because the rattle came from the bedroom wall.
- Found
- Loose trunking cover vibrating against the wall during fan operation
- Key check
- Held the trunking cover during operation and the rattle stopped
- Result
- The bedroom ran quietly after the trunking cover was fixed. The case stayed small because the check followed the vibration instead of the assumed component. That made the repair quick, explainable, and easy to verify before leaving. The owner also knew what to film if the sound ever returns at night, including the trunking beside the unit.
What we were told
The bedroom cooled normally, but a light rattling sound became obvious at night when the room was quiet. The owner thought the sound came from the indoor fan. It was worse at one fan speed and softer when the unit settled.
What we checked
We listened for where the vibration changed instead of assuming the fan was failing. The unit casing, louvre, nearby trunking, and wall cover were checked while the fan ran at the speed that made the complaint obvious. Older low-rise condos can have trunking covers that loosen slightly over time as rooms are cooled nightly.
Cooling and airflow were normal.
The rattle changed when the trunking cover was held.
The indoor fan did not scrape or pulse.
One trunking clip was loose near the wall bend.
What we found
The rattle came from a loose trunking cover vibrating against the wall, not from the indoor fan. The fan speed created enough vibration to make the cover chatter at night, when the room was quiet. Because the sound changed when the cover was held, the noise source was outside the aircon body. That made a fan motor quote unnecessary from the checks we had. The quiet bedroom made the sound feel larger than the actual fault.
What fixed it
We secured the trunking cover, checked the nearby clips, and ran the unit again at the same fan speed. We advised the owner to record future noise with both the unit and nearby trunking in frame, because wall-side vibration can sound like it comes from the unit. No indoor fan replacement was recommended because the rattle disappeared when the external cover was secured. The owner was also told to mention fan speed, because some loose covers only vibrate at one setting.
Outcome
The bedroom ran quietly after the trunking cover was fixed. The case stayed small because the check followed the vibration instead of the assumed component. That made the repair quick, explainable, and easy to verify before leaving. The owner also knew what to film if the sound ever returns at night, including the trunking beside the unit.
What this case teaches us
Bedroom rattles can come from nearby fittings
- A rattle near the indoor unit is not always inside the aircon. Trunking covers, casing edges, brackets, and wall fittings can vibrate.
- If touching a cover changes the sound, check fitment before approving fan motor work.
- Record the sound at the fan speed where it is loudest. Noise diagnosis depends heavily on timing and where the vibration changes.
Related reading
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