How to Remove Calcium Buildup From a Swamp Cooler

Hunker may earn compensation through affiliate links in this story.

Things You'll Need

  • Ladder

  • Vinegar

  • Bucket

  • Wire brush

  • Mild detergent

  • Water hose

  • Wrench

  • Screwdriver


Paint the area around your reservoir with a water-resistant rust-proof coating once yearly to avoid corrosion.

To winterize your unit, disconnect the water line and blow out all lines in the unit to avoid freezing during the winter.

Swamp coolers are evaporative air conditioning units that circulate air through wet pads to lower the temperature within your home. Because most water naturally contains calcium and minerals and these units work by continually circulating water throughout the system, calcium buildup can occur. An excess of scale can reduce the efficiency of your unit in addition to causing mechanical wear and breakdown over time. Cleaning your swamp cooler regularly will help reduce the caustic effects of mineral buildup and keep your unit running smoothly.

Step 1

Disconnect your swamp cooler from the power source and turn off the water. If your cooler is located above the home, climb onto the roof and remove the cooler-pad panels. Some will have metal panels, while others have metal bars holding the pads in place.

Step 2

Inspect the inside and outside of the unit for calcium buildup.

Step 3

Empty the drain pan. Combine three cups of white distilled vinegar with water in a bucket, and dip a wire brush into the mixture to scrub the louvers (venting) and drain pan. Scrub the fan blades, outside unit, water float and around the pump, if needed, removing excess calcium with the brush. Rinse all items with clean water.

Step 4

Unplug the drain fitting on the water reservoir and unscrew the overflow tube. Rinse the reservoir with a combination of vinegar and soapy water. Connect a garden hose to the drain fitting and flush the unit. Replace the overflow tube and drain fitting.

Step 5

Tighten all nuts located around all tube fittings. This will help stop any leaks and excess calcium buildup from forming inside the unit. Replace the cooler pads with new ones, if needed, and return them to the panels. Position panels correctly before reattaching to the unit. Return water and electricity to the unit.

references & resources

Abaigeal Quinn

Abaigeal Quinn works as an international entertainment broker in the United States. She is a former news editor and insurance agent who began writing for a daily newspaper in 1995.