Commercial Air Conditioner Not Cooling? What to Check First

When an office starts warming up or a retail tenancy begins receiving complaints, the facilities manager is often the first person asked to sort it out. During Perth’s summer, even a partial loss of cooling can affect staff, tenants and daily operations.

Sometimes, the equipment still appears to be working. Air is coming through the vents and the controller shows no obvious fault, but temperatures continue to rise. A maintenance report stating ‘air conditioner not cooling’ doesn’t tell you what’s gone wrong or how much of the building is affected.

Knowing where to start makes the situation easier to manage. A few safe checks can help establish what’s happening, identify warning signs and gather the information needed to arrange repairs.

Why Is the Air Conditioner Not Cooling When It’s Still Running?

On many commercial systems, the fan can keep circulating air even when the components responsible for cooling aren’t operating correctly. In other cases, the equipment may be working but struggling to keep up with the building’s cooling demand.

Restricted airflow is one possible cause, with dirty filters, blocked vents or debris around coils limiting cooling efficiency. Incorrect settings, faulty sensors and control issues can also prevent the system from maintaining the required temperature.

Other problems depend on the type of air conditioning installed:

• Refrigerated air conditioning: Refrigerant leaks, compressor problems or other mechanical and electrical faults can reduce cooling capacity.
• Evaporative air conditioning: Issues with water supply, pumps, cooling pads or fan operation can affect how well the system cools.

Increased heat load can also make it harder to maintain the required temperature, even when the equipment is running normally.

The building’s layout matters too. In larger commercial air conditioning systems, several zones may share equipment or central controls. A problem affecting one room may have a different cause from poor cooling across an entire floor.

What Your Facilities Team Can Check Safely

Your team can make a few initial checks using normal operating controls and safely accessible areas.

Before starting, look for immediate safety concerns. Smoke, burning smells or water near electrical equipment should be handled according to your site’s emergency procedures. For server rooms, substations and other controlled environments, follow established operating limits and escalation procedures rather than waiting to see if conditions improve.

If it’s safe to proceed, start with the following:

• Check the temperature settings and schedule. Confirm that cooling mode is selected, the set point is appropriate and the system is scheduled to operate during the building’s current hours. If you have a building management system (BMS), check for displayed alarms or schedule changes. A tenancy operating outside its usual hours, for example, may still be running on its normal cooling schedule.
• Look for blocked airflow. Furniture, stored stock, equipment and temporary partitions can restrict airflow. Check accessible air outlets and any relevant return or exhaust openings, particularly in warehouses, retail spaces and offices where layouts change regularly.
• Find out which areas are affected. Is the problem limited to one room, an entire floor or several zones? Identify the affected spaces and note any unit or zone identification numbers.
• Think about what’s changed on-site. Frequently opened loading doors, additional kitchen equipment or increased occupancy can introduce extra heat. If the system was previously keeping up with demand, consider any recent changes in how the building is being used.
• Record how the system is performing. Where readings are available, compare the affected space with areas cooling normally. Note the room temperature, set point and any unusual behaviour, such as temperatures continuing to rise while cooling is enabled.

Only authorised staff should adjust normal operating controls. Equipment panels, electrical isolation and refrigerant work must be left to appropriately qualified and licensed tradespeople.

The Warning Signs to Watch For

An air conditioner not cooling despite the correct settings may need more than a simple adjustment. Some symptoms suggest a fault that should be checked before further damage occurs.

Keep an eye out for:

• Ice or frost on pipework or indoor units: In refrigerated systems, icing can indicate restricted airflow or a refrigerant-related problem. If safe and permitted by site procedures, switch off cooling using the normal controller and arrange an inspection. Avoid removing the ice or repeatedly restarting the equipment.
• Water leaking around the unit: In refrigerated systems, blocked condensate drains and frozen evaporator coils are among the potential causes of water leaks in commercial air conditioning systems. Dripping water, damp ceiling tiles or pooling around equipment should be investigated before further damage occurs.
• Unusual noises: Grinding, knocking or rattling may indicate worn or damaged components, particularly if the noise has developed suddenly or is becoming louder.
• Repeated shutdowns or electrical trips: Recurring error codes, unexpected shutdowns or tripped electrical protection devices can indicate a fault. Don’t repeatedly reset breakers or override safety controls.
• Rooms that won’t reach their set point: If the system continues running but the space remains too warm, reduced cooling capacity, excessive heat load or control problems may be affecting performance.

If you’ve any issues that have accompanied these warning signs may require commercial air conditioning repairs, rather than further adjustments to the settings.

How to Report an Air Conditioning Fault

A report that simply says the air conditioning isn’t cooling gives little to go on. Include where the problem is occurring, when it started and what the unit is doing.

For example, noting that the west office zone has remained above its set point since mid-morning, while neighbouring areas are cooling normally, gives a much clearer picture.

Where available, include the unit or asset number, temperature readings, controller error codes and any BMS alarms. Mention if the fault has occurred before or if there have been recent changes to building operations.

For larger sites, include any access restrictions, permit requirements or critical operations affected by the fault. You don’t need to know which component has failed.

What to Expect During a Repair Visit

A technician will check the reported symptoms against how the equipment is operating. Depending on the system, this may involve reviewing controller settings and temperature readings, assessing airflow, inspecting fans and coils, or testing mechanical and electrical components. Refrigerated systems may need refrigerant circuit testing, while evaporative equipment may require checks of pumps, water distribution and cooling pads.

Different faults can produce similar symptoms, so testing helps establish what needs repairing. The findings can then be explained, along with any work required. Some faults may be resolved during the initial visit, while others need replacement parts, further testing or more extensive repairs.

Maintenance history may also be relevant, particularly if dirt buildup, worn components or missed servicing have contributed to the problem. A suitable commercial air conditioning servicing schedule should account for how often the equipment runs and the conditions on-site.

Get Your Commercial Air Conditioning Back on Track

If your commercial air conditioning is struggling to maintain temperature or showing signs of a fault, it’s worth having the problem checked before it gets worse.

At Perth Air & Power Solutions, we provide commercial air conditioning repairs across Perth, backed by over 15 years of industry experience. With expertise in both electrical and refrigeration systems, we can investigate faults involving either trade, giving you one provider to deal with throughout the repair process.

Contact our team today to discuss what’s happening and arrange a visit to your site.

Frequently Asked Questions