Is it normal for a new aircon to need time to cool properly?

No. A correctly installed and charged unit cools to its rated capacity from day one. There is no break-in period for air conditioning systems. If a new unit is underperforming from the day of installation, the installation itself should be investigated. The most common causes are undercharge, incorrect pipe sizing, or a restriction introduced during installation.

Why would an installer leave it undercharged?

The most common reason is that the installer did not connect gauges and verify the final pressure against the manufacturer's specification. Some installers rely on factory pre-charge plus a fixed top-up amount based on pipe length without checking the actual result. This is an installation process gap, not a product defect.

Do I need to pay for this correction?

If the undercharge occurred at installation, the cost of correction should sit with the installing company — it is part of completing the job correctly. Whether the original installer will accept responsibility depends on your installation contract. We can provide the pressure measurements before and after the top-up as documentation to support a conversation with the original installer.

New installation not cold due to undercharge at handover

Aircon case in Tampines, Singapore: post-service issue traced to refrigerant charge significantly below specification — unit undercharged during installation after targeted diagnosis checks.

Case details

What client reported

The customer said the unit had been installed two weeks earlier and had never cooled the bedroom to the set temperature. At 24°C, the room hovered around 27–28°C even after running for two hours. The installer had visited once and told them it was normal for new units to take time to reach full performance.

ProblemPost-service

UnitDaikin · Wall-mounted · Under 3 years

LocationHDB · Tampines, Singapore

What we found

A new unit that is not reaching set temperature has a very short list of causes — we went straight to measuring refrigerant pressure

Low-side pressure measured at 4.2 bar in cooling mode — correct value for this Daikin model at the ambient conditions should be 6.5 to 7 bar
High-side pressure correspondingly low, confirming undercharge rather than a restriction or expansion device fault
Leak check performed on all pipe connections, flare joints, and service ports — no leak detected. The charge had simply been set too low at installation.
Airflow and coil condition checked — filter clean, coil unobstructed, both indoor and outdoor units running normally apart from the refrigerant deficit

The unit had been undercharged at installation. The refrigerant level was approximately 35% below specification for the pipe length and ambient conditions. Either the charge was not verified with gauges at installation, or the gauge reading was not compared against the manufacturer's specification. This is an installation deficiency.

What we did

Refrigerant was added to bring the charge to the correct specification for the installed pipe length. Low-side pressure was re-measured and confirmed within the correct range. The unit was run through a full cooling cycle. Room temperature dropped to the set point within the expected time — the first time this had happened since installation.

The unit has been performing correctly since the charge correction. The customer was advised to contact the original installer about the installation quality. An undercharge should have been caught before handover. A correctly charged system does not need a top-up within the first two weeks of operation.

Timeline

Day 1

Unit installed — customer noticed cooling was weaker than expected from the start

Day 14

Low-side pressure measured well below normal operating range for the ambient conditions — confirmed undercharge, not a leak

Day 14

Refrigerant pressure measured below specification, undercharge confirmed, charge corrected to specification, cooling immediately improved to expected level

What we learned

New installations should cool properly from day one.

A correctly installed and fully charged unit cools to its rated capacity from the first day of operation. There is no settling-in or break-in period for air conditioning systems.
Undercharge at installation happens when the installer does not verify refrigerant pressure against the manufacturer's specification. It is an installation quality issue.
The symptoms of an undercharged new unit are the same as a unit that has lost refrigerant over time. The compressor runs and airflow is normal, but the air is not as cold as it should be.
The installing company is responsible for verifying the charge before handover. If they did not, the correction should be done at no additional cost to the customer.

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