Could this be a refrigerant issue even though only one room is affected?

On a split system for that room only, yes — low refrigerant would affect just that unit. On a multi-split system serving multiple rooms, low refrigerant on the shared outdoor unit would usually affect all rooms to varying degrees, not just one. The configuration of your system matters in the diagnosis.

My room has always been harder to cool. Is that normal?

It can be. West-facing rooms, rooms above a kitchen, and rooms with large uncovered windows are harder to cool. If the unit was borderline on capacity for the room size from the start, it may only become noticeable on hotter days. We can assess whether the unit is the right size for the room.

Should I service just the unit in that room, or all of them?

If only one room is affected and others are fine, start with the unit in the affected room. There is no need to commit to a full-home service until you have confirmed what is wrong with the one unit.

The unit in that room has a flashing light. What does that mean?

Flashing lights are the unit flagging a fault code. Different patterns mean different things depending on the brand. Share the brand, model, and the flashing pattern on WhatsApp and we will tell you what the code indicates and whether it needs immediate action.

Aircon Not Cooling One Room

When one room is warm and the rest of the home cools normally, the fault is usually local — either the unit serving that room or something specific about the room itself. This article helps you read the pattern before spending on a diagnosis.

Common Causes

A symptom is just a starting point. The same problem could be a quick fix or a major failure. The paths below show the most common causes, but only a proper check can prove what is really wrong.

Filter or Coil Clogged on That Unit

Usually Minor

If this room has its own indoor unit and the filter is heavily soiled, airflow drops and cooling performance falls noticeably. The other rooms are unaffected because they have separate units with cleaner filters.

Airflow from the indoor unit in that room feels weak compared to other units.
The unit is running but the room stays warm.
Other rooms on the same system cool normally without issue.

The Fix: A proper diagnosis is required to confirm the exact root cause and determine the necessary repair.

Watch out: If the filter was recently cleaned and the issue persists, the coil itself may be dirty. A general service can confirm whether the coil needs a deeper clean before jumping to repair.

Fault on the Indoor Unit for That Room

Needs Diagnosis

Specific components in the indoor unit — the fan motor, thermistor, or indoor PCB — can fail on one unit without affecting others. Each fault produces different signs, which is why on-site checking is needed before deciding what to replace.

The indoor unit in that room is running but not producing cold air, or producing no airflow at all.
The unit shows a flashing light or error code on the display.
Other indoor units in the home are cooling fine.

The Fix: A proper diagnosis is required to confirm the exact root cause and determine the necessary repair.

Watch out: Error codes are a starting point, not a confirmed diagnosis. The same code can be triggered by multiple faults. Get the code checked before approving any part replacement.

Room Conditions Are the Issue

Usually Minor

Some rooms are harder to cool even with a working unit — west-facing rooms, poorly insulated ceilings, rooms with large glass areas, or rooms that connect directly to a kitchen or outdoor space.

The unit blows cold air but the room temperature stays high.
It is worse in the afternoon and better at night.
The unit in this room has always struggled compared to others.

The Fix: A proper diagnosis is required to confirm the exact root cause and determine the necessary repair.

Watch out: Increasing refrigerant or upgrading the service will not solve a room heat-load issue. If this is the case, we will tell you honestly on assessment. The solution is usually supplementary cooling or room treatment.

Not Always A Fault — Room Conditions Vary More Than Expected

Even with a fully working aircon, some rooms are harder to cool. A room above the kitchen, a converted study room, or a bedroom with west-facing glass will naturally run warmer. These differences can appear suddenly when weather gets hotter or when the room's use changes.

How to tell if the room is the variable

The aircon in the room produces strong airflow and feels cold at the vent.
The room warms up quickly when the unit is off, faster than other rooms.
Heat sources in the room — appliances, people, sunlight — have increased recently.

If we find the unit is working and the room is the problem, we will say so on assessment. No repair will be recommended that does not address the actual cause.

What To Note Before You Contact Us

Observe with the unit in that room running:

Airflow strength from the indoor unit: strong, weak, or no airflow at all.
Whether any lights are flashing or an error code is visible on the unit.
Whether other rooms in the home are cooling normally at the same time.
Room conditions: sun direction, appliances running, doors in use during the test.

These details narrow the fault to a unit issue or a room issue before we need to visit.

Stop Using The Unit If You Notice These

These are safety signals, not cooling performance faults.

Burning or electrical smell from the indoor unit in that room.
Breaker tripping when that unit is switched on.
Water dripping from the indoor unit onto electrical points or flooring.

Aircon Not Cooling One Room

Common Causes

Filter or Coil Clogged on That Unit

Fault on the Indoor Unit for That Room

Room Conditions Are the Issue

Not Always A Fault — Room Conditions Vary More Than Expected

How to tell if the room is the variable

What To Note Before You Contact Us

Stop Using The Unit If You Notice These

Common Questions

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