The cooling pad is the part of an evaporative cooler that does the actual work, and it needs more regular attention than the rest of the unit.
Empty and rinse the tank regularly
Standing water left in the tank between uses, as with any water-holding appliance, can develop odor and support algae or bacterial growth — empty and rinse it rather than continuously topping it up.
Rinse the pad itself periodically
Mineral deposits from tap water accumulate on the pad over time, especially in hard-water areas, reducing how effectively it absorbs and evaporates water. A gentle rinse under clean water, following your model’s guidance on removing the pad safely, clears much of this buildup.
Watch for a musty smell as an early sign
A persistent odor, even after cleaning, often means the pad has retained enough mineral or organic buildup that cleaning alone isn’t fully resolving it — this is usually when replacement becomes the more effective option.
Dry the unit fully before storing it
At the end of a season, run the cooler with an empty tank briefly to dry the pad, rather than boxing it away wet — see our seasonal storage guide for the fuller routine.
What we would not do
Suggest a fixed replacement schedule that applies to every model and every water hardness. Follow your specific unit’s guidance, and treat a persistent smell or visibly degraded pad as the practical signal to replace it rather than a calendar date.
The questions that keep coming up
How often does the pad need replacing entirely?
It varies by usage and water hardness — check your specific model's guidance. A pad that's visibly discoloured, brittle, or producing a persistent odor despite cleaning is generally due for replacement rather than further cleaning.
Last reviewed 24 August 2026