Brand-new BTO unit never felt cold: undercharged from install
A brand-new aircon in a Tengah BTO flat had never cooled since the day it was installed. The installer suspected a faulty compressor and pushed a warranty claim. But a unit that was never cold reads very differently from one that worked and then stopped.
By Team Snowflake | Reviewed 11 Mar 2026
Case summary
Midea Wall-mounted1 years oldHDBTengah, Singapore
- Concern
- The family feared the brand-new compressor was defective and would need a warranty replacement, leaving the master bedroom without cooling for weeks.
- Found
- Refrigerant charge was insufficient for the actual pipe run length, the installer had not topped up beyond the factory pre-charge
- Key check
- Checked gas readings and compared the factory pre-charge allowance against the actual pipe run before suspecting the compressor
- Result
- The master bedroom cooled down for the first time since the family moved in. No parts were replaced, and no warranty claim was filed. The unit has cooled normally since the top-up, and the weeks of waiting the family had braced for never happened.
What we were told
The aircon went in when the BTO flat was handed over and was never cold. Air came out of the unit, but it was barely cooler than the room. The installer came back, said the compressor might be defective, and recommended a warranty claim that could take weeks. The master bedroom had stayed warm since the family moved in.
What we checked
A unit that was never cold from day one points to how it was set up, not to a part that wore out. A compressor that has run for one day rarely fails on its own. So we checked the refrigerant charge against the pipe run before suspecting the compressor.
The compressor was running and cycling normally. No unusual sounds, no tripping, no error codes. A failing compressor would show at least one of these.
Air from the indoor unit was warmer than expected, which fits a system low on refrigerant rather than a dead compressor.
We measured the gas readings, and they sat below where a healthy charge should be.
The pipe run from the indoor to the outdoor unit was longer than the standard factory pre-charge covers.
After topping up the refrigerant to match the actual pipe length, the indoor unit began blowing cold air within minutes.
What we found
The factory pre-charge in the outdoor unit was sized for a shorter pipe run than the BTO layout needed. A longer run holds more refrigerant, so the installer should have added extra at install. That step was skipped. The system ran undercharged from the first day. The compressor was healthy, but it never had enough refrigerant to cool the room.
What fixed it
The compressor was not defective. The system was undercharged for the pipe run length. We told the family a warranty claim was not needed and topped up to the correct charge for the actual run. The unit started cooling properly once the charge was right.
Outcome
The master bedroom cooled down for the first time since the family moved in. No parts were replaced, and no warranty claim was filed. The unit has cooled normally since the top-up, and the weeks of waiting the family had braced for never happened.
What this case teaches us
Never cold from day one usually means a setup miss, not a broken part
- A new unit that was never cold points to how it was installed, not to a part that failed. The compressor had no track record to break from.
- Every pipe run has a length the factory charge covers. A longer run needs extra refrigerant added at install, and that step is easy to skip.
- Before agreeing to a warranty claim or a part swap, ask whether the refrigerant charge was matched to the actual pipe run.
Related reading
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