Winterizing Your Evaporative Cooler
2 min read
Mold smell in spring or a cracked water line? You skipped shutdown steps. Drain, dry, seal the interior duct — then install the cover last.
Need the quick reference first? Full maintenance & storage guide
Problem: Covering Too Early or While Wet
A cover on a wet unit traps moisture → rust, mold, and pad rot by spring. Shut down when nights stay below ~50°F and you will not need cooling again until spring. The cover is the last step, not a substitute for draining.
Solution: Shutdown Checklist
Do these in order. Cleaning detail and storage tips are in the maintenance guide.
- Power off at the disconnect — not just the wall switch
- Close the water valve; disconnect and blow out the feed line
- Drain the pan completely; leave the drain plug open
- Scrub the pan; inspect pads — replace damaged ones or dry fully before covering
- Seal the interior duct opening inside the house (damper or insulated panel)
- Install cover — correct draft type, hem below lowest louver, tie-downs if exposed
If You Already Have These Symptoms
- Mold smell when you remove the cover → unit was wet; drain and dry fully next season
- Cracked feed line in spring → line was still full of water when it froze
- Still cold indoors → interior duct not sealed — cover alone does not fix in-house draft
- Cover on the ground after a storm → add tie-downs; see installation guide