7 Signs Your Evaporative Filter Pads Need Replacing (And What To Do Next)

Evaporative coolers are a great way to stay comfortable during hot Australian summers. They’re affordable, energy efficient, and work well in dry climates like Perth. But like any appliance, parts wear out over time—especially the evaporative cooling filter pads, which affect both performance and the quality of the air you breathe.

Indoor air quality is a concern worldwide. Poor indoor air can contribute to breathing problems, heart issues, and other long-term health risks. When filter pads are old or dirty, they don’t just reduce cooling—they can also affect how fresh and clean your air feels.

If you’re unsure whether it’s time to replace your filter pads, watch for some simple warning signs. Acting early helps you avoid bigger problems and reduce the risk of costly repairs.

Why Evaporative Filter Pads Matter

The filter pads in an evaporative cooler do all the heavy lifting. As warm outside air passes through the pads, the water held in the material evaporates and cools the air. That cooled air then gets circulated into your home. When your evaporative filter pads are clean and in good condition, they cool effectively and use less energy. But when they’re worn, clogged or damaged, your system will struggle, use more water and power, and may even release unhealthy air indoors.

1. Your Cooler Isn’t Blowing Cold Air

If your evaporative cooler is running but the air feels lukewarm or barely cooler than the outside air, your filter pads could be the culprit.

• Why it matters: Pads that are clogged or dry can’t hold enough water to produce the cooling effect.
• What to do: Check the pads for dryness or damage. Replacing old evaporative cooler filter pads usually restores effective cooling straight away.

2. You Notice A Musty Or Unpleasant Smell

A musty, damp, or mouldy smell coming from your vents can be a sign your filter pads are overdue for replacement.

• Why it matters: As pads age, they can harbour bacteria, mould and mildew—especially if they’re not drying properly between uses.
• What to do: Replace the pads and clean the internal components. Let the cooler dry out fully between uses to help prevent future odours.

3. The Pads Are Discoloured Or Falling Apart

Sometimes you can spot the problem just by looking. If your pads look discoloured, cracked, brittle or are breaking down, it’s time for a fresh set.

• Why it matters: Damaged filter pads can’t hold water evenly, which leads to poor airflow and uneven cooling.
• What to do: Always replace worn-out pads with the correct size and type for your unit. Quality matters here.

4. Your Energy Or Water Bills Have Spiked

Noticing your water or power bill creeping up during cooling season? It might be because your system is working harder than it should.

• Why it matters: When filter pads are blocked or inefficient, the fan has to work harder, and more water may be used to try and achieve the same cooling output.
• What to do: Replacing the pads can reduce energy and water use—saving you money over the season.

5. You Hear Strange Noises

Evaporative coolers are generally quiet. If yours is suddenly making odd noises—like squealing, grinding, or rattling—it could mean something is wrong inside.

• Why it matters: Loose or degraded pads can shift around, block fans or cause internal parts to strain.
• What to do: Replace the pads and get the unit checked to ensure all moving parts are working properly.

6. It’s Been Over A Year Since Your Last Pad Change

Most evaporative air conditioner filter pads should be replaced at least once a year—ideally before summer starts.

• Why it matters: Even if they look okay, filter pads lose efficiency over time. Their structure breaks down and they no longer hold or distribute water properly.
• What to do: Make it part of your regular spring maintenance routine. A new set of pads ensures your system runs efficiently all summer.

7. You Have Allergies Or Respiratory Irritation

If you or someone in your household is sneezing more, experiencing itchy eyes or other allergy-like symptoms when the cooler runs, dirty or mouldy pads could be spreading allergens.

• Why it matters: Old filter pads can release dust, pollen and mould spores into your home.
• What to do: Replace the pads and thoroughly clean the internal components. You’ll likely notice better air quality almost immediately.

What To Do Next: Replacing Evaporative Filter Pads

Not all pads are created equal. When replacing evaporative filter pads, consider:

• Correct sizing: Pads must fit properly to work well. Too small and they’ll let unfiltered air through; too big and they’ll get crushed.
• Material: Some systems use cellulose pads (good for affordability), others use rigid media or synthetic pads (more durable).
• Compatibility: Always check your cooler brand and model when buying new pads.

When To Call A Professional

Changing your filter pads is often straightforward, but it’s worth calling a licensed technician if:

• You’re unsure what size or type of pad to use
• Your cooler is older or hard to access
• The cooler still doesn’t work after pad replacement
• You notice leaks, rust, or electrical issues

Keeping Your Evaporative Cooler In Top Condition

Regular pad replacement is one part of keeping your cooler healthy, but here are some extra tips to get the best from your system:

• Clean the water tank: Once a season, drain and scrub the tank to remove sediment and slime.
• Flush the system: Run a full cycle with clean water every few weeks to prevent build-up.
• Inspect the pump: A faulty pump can stop water reaching the pads.
• Cover it in winter: Use a cover to keep out dust, debris, and birds when not in use.

Benefits Of Regular Filter Pad Replacement

• Better cooling: Fresh pads = cooler air.
• Healthier air: Reduces mould and allergens.
• Lower costs: Saves money on energy and repairs.
• Longer lifespan: Prevents wear and tear on internal parts.

Frequently Asked Questions

What happens if I don’t replace my evaporative filter pads?

If you don’t replace old or worn-out pads, your cooler won’t work as effectively. Airflow is reduced, cooling is uneven, and the motor may work harder than it should. This can also lead to higher energy use and possible damage to the unit. Over time, it can result in more expensive repairs or even early replacement of the entire system.

How often should I replace my evaporative cooling pads?

Most evaporative filter pads should be replaced every 1–3 years depending on usage, water quality, and climate. In areas like Perth with mineral-rich water and frequent use, annual replacement may be needed. Always check the manufacturer’s guidelines, and inspect your pads before each cooling season begins.

Can I replace the evaporative pads myself or do I need a professional?

Some homeowners in Perth choose to replace their evaporative pads themselves, especially if they are comfortable with basic maintenance tasks. However, a professional can ensure the correct pads are used and check for other potential issues while they’re there. It’s a good opportunity to service the unit at the same time.

Do dirty pads affect indoor air quality?

Yes, they do. Dirty or mouldy evaporative pads can allow bacteria, allergens, and bad smells to circulate inside your home. This can impact people with allergies, asthma, or sensitivities. Keeping pads clean or replacing them regularly helps maintain healthy indoor air.

Is it more cost-effective to replace just the pads or the entire unit?

Replacing the pads is almost always the more cost-effective option if the rest of the unit is in good condition. However, if your evaporative cooler is over 10 years old, frequently breaking down, or showing signs of corrosion or motor failure, a full replacement might be the better long-term investment.

Book Expert Filter Pad Replacement In Perth With Joondalup Heating & Cooling

Don’t wait until your cooler breaks down in the middle of a hot Perth day. Trust Joondalup Heating & Cooling to help with fast and reliable evaporative filter pad replacement in Perth. Our experienced team knows the local climate and can recommend the best options for your system. We proudly serve Perth and surrounding areas with quality parts, expert advice, and friendly service.

Call Joondalup Heating & Cooling today to schedule your evaporative pad replacement in Perth and keep your system running at its best.