When your evaporative air conditioner stops working properly, it can quickly become uncomfortable inside your home, particularly during a hot Adelaide summer. You might find that the unit will not turn on, the fan is running but the air is not cool, the water pump is not working, or the system is producing very little airflow.

The good news is that these symptoms can help narrow down the possible causes. An evaporative air conditioner relies on several components working together, including a fan, water pump, cooling pads, water supply, controls and ductwork. A problem with any of these components can affect the system's performance.

In this guide, we explain nine common reasons an evaporative air conditioner or evaporative cooler might not be working, what you can safely check yourself, and when to arrange professional repairs.

If your system has developed a persistent fault, Prompt Plumbing and Air provides evaporative air conditioning repairs, servicing and replacement across Adelaide.

What to Check First When Your Evaporative Cooler Stops Working

Before assuming that your evaporative cooler needs repairing, start with a few simple observations.

Check the controller settings

Confirm that the unit is switched on and that the controller is set to the correct operating mode. Check the fan speed, timer and any programmed settings. Some systems have separate fan and cooling functions, so running the fan does not necessarily mean the water pump is operating.

Check the power supply

If the unit will not start, look for an obvious power interruption or a controller display that is not responding.

Do not open electrical compartments, remove covers or repeatedly reset a circuit breaker that trips. Electrical faults need to be assessed by an appropriately qualified professional.

Check the airflow inside your home

If the system appears to be running, check whether air is coming through the ceiling outlets.

Weak or absent airflow may indicate a fan, motor, ductwork, outlet or control problem.

Note when the problem started

Think about whether the problem appeared suddenly, developed gradually or only occurs under particular weather conditions. These details can help a technician identify the likely cause more efficiently.

Important: Do not climb onto the roof or attempt to repair electrical, mechanical or water-system components yourself. The checks above are limited to normal controller operation and safe observations from inside the home.

Not sure what is causing the problem?

Read our guide to common evaporative air conditioner problems and what to do before arranging a repair.

9 Common Reasons an Evaporative Air Conditioner Is Not Working

The following problems cover common symptoms, possible causes and sensible next steps. A symptom alone does not confirm which component has failed.

1. The Evaporative Air Conditioner Will Not Turn On

If your evaporative air conditioner will not start at all, the problem may involve the power supply, controller, wiring, motor or another electrical component.

Possible causes include:

• A controller that is switched off or incorrectly configured.
• A power supply interruption.
• A faulty controller or electrical connection.
• A motor or control-system fault.
• A protective device that has tripped because of an underlying problem.

What you can do: Check the controller and note whether the display responds. If the unit remains unresponsive, arrange professional fault finding. If a circuit breaker trips repeatedly, do not keep resetting it. The underlying fault needs to be investigated.

When to call a technician: If the system will not start after basic controller checks, or you notice electrical smells, unusual noises or repeated power interruptions, arrange a professional assessment.

2. The Fan Is Running, but the Air Is Not Cool

One of the most frustrating evaporative cooler problems is a fan that runs normally without delivering the expected cooling. Evaporative air conditioning cools incoming air as it passes through water-moistened cooling pads. If the water circulation or evaporation process is not working properly, the air may feel much warmer than expected.

Possible causes include:

• A water pump that is not operating correctly.
• Insufficient water reaching the cooling pads.
• Dirty, blocked or deteriorated cooling pads.
• Problems with water distribution.
• Poor airflow or ductwork issues.
• High outdoor humidity reducing cooling effectiveness.

What you can do: Confirm that the controller is set to cooling mode, rather than fan-only mode. Consider whether the weather is unusually humid and note whether the problem occurs throughout the home.

When to call a technician: If the fan runs but cooling remains poor in otherwise suitable conditions, arrange an inspection of the pump, water distribution, cooling pads and airflow.

3. The Evaporative Cooler Is Blowing Warm Air

An evaporative cooler can appear to be working while providing very little cooling.

This can happen when the water supply is insufficient, the cooling pads are not getting wet properly, or the outdoor conditions are making evaporation less effective.

Unlike refrigerated air conditioning, evaporative cooling relies on water evaporating into the incoming air. Its performance therefore changes with outdoor temperature and humidity.

Possible causes include:

• Cooling pads that are dirty or deteriorated.
• Inadequate water flow.
• A pump or water distribution fault.
• Fan or airflow problems.
• Outdoor humidity that limits evaporation.
• Incorrect operating settings.

What you can do: Check the controller settings and consider whether the weather conditions have changed. If the system has recently lost its cooling performance, do not assume that the weather is the only explanation.

When to call a technician: If the cooler continues blowing warm air despite appropriate settings and favourable conditions, have the water system, pads and airflow assessed.

4. The Evaporative Cooler Fan Is Not Working

If there is little or no air coming through your ceiling outlets, the problem may involve the fan or motor rather than the cooling process itself.

Possible causes include:

• A motor fault.
• An electrical or control fault.
• A mechanical obstruction.
• Damaged or worn fan components.
• An incorrect controller setting.

What you can do: Check the fan setting on the controller and observe whether the system responds when switched on.

Do not remove the unit's covers or attempt to access moving parts.

When to call a technician: If the fan does not start, stops unexpectedly or makes unusual mechanical noises, arrange a professional inspection.

5. The Evaporative Cooler Water Pump Is Not Working

The water pump is an important component of an evaporative air conditioning system. It circulates water to keep the cooling pads wet.

If the pump fails or water is not distributed properly, the fan may continue operating while the system provides little cooling.

Possible causes include:

• A failed or worn pump.
• An interrupted water supply.
• A water-level or float-valve problem.
• Blocked water distribution components.
• An electrical or control fault.

What you can do: Check for changes in cooling performance and note whether the fan operates without effective cooling. Do not open the rooftop unit to inspect the pump.

When to call a technician: If the system is not cooling and a water pump fault is suspected, professional diagnosis can determine whether the problem involves the pump, water supply, controls or another component.

6. The Evaporative Cooler Has Weak Airflow

Sometimes the system runs, the water pump appears to be operating, and the air feels somewhat cool, but very little air reaches the rooms.

Weak airflow can make an evaporative cooler seem ineffective even if the water system is functioning.

Possible causes include:

• Restricted or dirty cooling pads.
• Fan or motor deterioration.
• Blocked or restricted ductwork.
• Damaged ducting.
• Obstructed ceiling outlets.
• Incorrect fan settings.

What you can do: Check that the controller is set to the intended fan speed and that accessible ceiling outlets are not obstructed by furniture or other items.

Compare airflow between rooms to see whether the problem affects the whole home or only certain outlets.

When to call a technician: If airflow remains weak, a professional can assess the fan, pads, ductwork and air distribution.

7. The Evaporative Air Conditioner Is Leaking Water

A leaking evaporative cooler should not be ignored, especially if water may be entering the roof space.

Water leaks can arise from several parts of the water supply and drainage system.

Possible causes include:

• A faulty float valve or water-level control.
• A problem with the water supply connection.
• Blocked or faulty drainage.
• A damaged water connection.
• A pump or water distribution issue.
• An internal component fault.

What you can do: If it is safe, switch the system off using its normal controls and observe whether there is visible water damage inside the home. Avoid accessing the roof or handling electrical equipment near water.

If water is entering the ceiling or roof space, treat the problem promptly.

When to call a technician: Arrange an inspection to identify the source of the leak and prevent further damage.

8. The Evaporative Cooler Is Making Unusual Noises or Smelling Musty

Unusual noises and persistent unpleasant smells can indicate that an evaporative cooler needs attention.

A new rattling, grinding or squealing sound may suggest a mechanical problem. A musty smell may be associated with dirty components, water-system issues or a need for maintenance.

Possible causes include:

• Worn or deteriorating mechanical components.
• Fan imbalance or loose components.
• A motor or pump fault.
• Debris within the system.
• Dirty or deteriorated cooling pads.
• Water-system or maintenance problems.

What you can do: Note the type of noise or smell and whether it occurs when the fan starts, while cooling is operating or when the system shuts down.

If the noise is severe or the system appears unsafe, switch it off using the normal controls.

When to call a technician: Arrange an assessment if the symptoms persist, become worse or occur alongside poor cooling, leaks or intermittent operation.

9. The Evaporative Cooler Works Intermittently

If your evaporative air conditioner starts and stops unexpectedly, the problem may be difficult to identify without a systematic inspection.

Possible causes include:

• Controller or control-system faults.
• Electrical interruptions.
• Motor or pump problems.
• Water-level or supply issues.
• A component that fails intermittently.
• Incorrect timer or operating settings.

What you can do: Note when the unit stops, whether the controller display changes, whether the fan continues running and whether the fault occurs at particular times.

Avoid repeatedly restarting a system that trips electrical protection or displays signs of an electrical fault.

When to call a technician: If the problem keeps returning, professional fault finding can help identify the underlying cause instead of relying on repeated resets

Evaporative Cooler Not Working? Diagnose It by Symptom

Use this table to narrow down what might be happening. These are possible causes, not definitive diagnoses.

If you need professional assistance,

see our evaporative air conditioning installation, repairs and servicing page.

Can Humidity or Hot Weather Make an Evaporative Cooler Stop Cooling?

Yes. Weather conditions can significantly affect how well an evaporative cooler performs.

Evaporative cooling works by drawing air through water-moistened pads. As water evaporates, it absorbs heat from the air. When outdoor air is relatively dry, evaporation is generally more effective. When humidity rises, the cooling effect becomes less pronounced.

This means that an evaporative cooler can be operating normally yet provide less cooling on a humid day.

However, reduced performance should not automatically be blamed on the weather.

If your system has suddenly stopped cooling, has developed weak airflow or is showing other unusual symptoms, there may be a mechanical, water-system or control fault as well.

For broader information about system operation, maintenance and installation,

read our Complete Adelaide Guide to Evaporative Air Conditioning.

When Should You Call an Evaporative Air Conditioning Technician?

Some basic checks can help you identify the symptoms, but many evaporative cooler faults require professional diagnosis.

Arrange an inspection if:

• The unit will not start.
• The fan runs but cooling is consistently poor.
• The water pump appears not to be operating.
• Airflow is weak or absent.
• Water is leaking from the unit.
• The fan or motor makes unusual noises.
• The system repeatedly stops or trips electrical protection.
• The controller does not respond correctly.
• The system has recurring faults despite servicing.

Do not attempt electrical repairs, remove protective covers or climb onto the roof to inspect the equipment yourself. A qualified technician can inspect the relevant components, identify the fault and explain the available repair options.

If your evaporative air conditioner is not working properly, Prompt Plumbing and Air provides evaporative air conditioning repairs, fault finding and servicing across Adelaide. Our service page covers repairs for common problems involving fan motors, water pumps, electrical faults, cooling pads and other system components.

We also provide installation, replacement and servicing for major evaporative air conditioning brands, including Bonaire, Breezair, Coolair, Braemar, Rinnai, Brivis and Kaden.

The right solution depends on the condition of your unit, the cause of the fault, the availability of parts and the likely value of the repair. For some systems, a straightforward repair may be appropriate. For older units with multiple deteriorating components, it may be worth comparing the repair cost with replacement.

To discuss your system, visit our evaporative air conditioning repairs and servicing page

or contact Prompt Plumbing and Air on 0402 644 229.

Frequently Asked Questions About Evaporative Coolers Not Working

Why has my evaporative air conditioner suddenly stopped working?

A sudden failure can involve the power supply, controller, fan motor, pump, water system or another component. Check the normal controller settings first, then arrange professional diagnosis if the system remains unresponsive.

Why is my evaporative cooler running but not cooling?

Possible causes include a water pump problem, inadequate water distribution, dirty cooling pads, poor airflow or high outdoor humidity. The symptoms and operating conditions help determine what needs to be checked.

Why is my evaporative cooler fan working but the pump is not?

The cause may involve the pump itself, the water supply, water-level controls, wiring or the controller. A technician can test the relevant components and identify the fault.

Can I reset my evaporative air conditioner?

You can check the normal operating controls and follow the manufacturer's instructions for ordinary controller operation. Do not repeatedly reset a circuit breaker that trips, bypass safety controls or open electrical compartments.

Why is my evaporative air conditioner leaking water?

Possible causes include a float valve problem, faulty water connection, drainage issue or internal component fault. If water is entering the roof space, arrange an inspection promptly.

Is it better to repair or replace an old evaporative cooler?

That depends on the age and condition of the system, the fault, the cost of repairs and the availability of replacement parts. A professional assessment can help you compare the options.

How often should an evaporative air conditioner be serviced?

Annual servicing before the main cooling season is a sensible approach for many residential systems.

Follow the manufacturer's recommendations and consider earlier attention if the unit has developed faults or is performing poorly.

Get Help With an Evaporative Air Conditioner That Is Not Working

An evaporative air conditioner can stop working for many reasons, from incorrect controller settings and water supply problems to fan faults, leaking components and reduced cooling performance in humid weather. Checking the basic settings and observing the symptoms can help you understand the problem, but persistent faults often need professional attention.

If your evaporative cooler is not turning on, is blowing warm air, has weak airflow or is leaking water, Prompt Plumbing and Air can help assess the issue and explain the next steps. For evaporative air conditioning repairs, servicing or replacement in Adelaide, visit our evaporative air conditioning service page.

Need help with your evaporative cooler?

Call Prompt Plumbing and Air on 0402 644 229.