How to Get Your Master Cool Evaporative Cooler Ready to Go for the Summer

Turn the power off to the cooler and unplug it. Let others in the house or building know you are cleaning the cooler. A cooler has moving parts that can cause physical harm if turned on while you are working on it. Take off the access panel and set it aside.

Remove the frames that hold the pads. Check the pads to see if they have a white buildup of mineral deposits on both sides. Clean off any light buildup using a stiff brush. If the buildup is heavy and covers both sides of the pad or pads, you may need to replace them or use a hose and nozzle set on the high-pressure setting to force the minerals off.

Clean off any mineral buildup off the fins of the frame with a hard plastic knife or tool. Avoid using metal on the frame since sharp metal objects can scratch or chip the paint on the frame, causing it to rust when using water in the cooler.

Place the pads back into the frames. Mastercool pads are rigid and it may take some effort to work them back into place. If you do not need to run the cooler immediately, wait until the pads are dry. Once the water has evaporated, the pads are lighter and easier to manage.

Inspect the bottom of the cooler for any mineral deposits. If dust or deposits are present, remove the overflow drain from the cooler and sweep the deposits out of the cooler through the drain, replacing it when you have finished. If you see any places where the water pan has started to rust, coat the base of the cooler with cooler tar to stop the rusting. You can find products to coat the cooler at hardware or plumbing stores. Let the coating dry before running water into the cooler.

Turn on the water supply for the cooler and let the water fill the pan, checking for leaks coming from the overflow pipe. Adjust the float if the water level is too high or too low by bending the float up if the water shuts off too soon or down if the water overflows.

Oil both sides of the shaft that turns the squirrel cage and close the caps that cover the fill holes.

Replace the access panel to the cooler, plug it back in and turn the water pump on to moisten the pads. When wet, turn on the motor and make sure everything is working properly.