Swamp cooler not cooling? What to check first
A quick checklist before you call for repair.
Quick answer: If a swamp cooler is not cooling, check humidity, power, water supply, pad wetness, pump, belt, and open windows. Dry or mineral-caked pads, a dead pump, or no water are the usual causes, and high humidity limits any swamp cooler. Call a contractor for motor, wiring, or roof work.
Safety. Turn off power before you open the cooler. Do not climb a wet or steep roof. Call a contractor if you are unsure.
| Symptom | Common causes | Check |
|---|---|---|
| Warm air | Dry or crusted pads, no water, dead pump, high humidity | Pad wetness, water supply, pump |
| Weak airflow | Slipping belt, failing motor, clogged pads, closed vents | Belt, pads, open a window |
| Musty smell | Old or constantly wet pads, dirty pan | Replace pads, clean pan |
| Water leak | Float valve, water line, cracked pan | Float, line, pan seams |
| Will not start | Breaker, switch, motor, wiring | Breaker; then call for service |
When to call a contractor
- The motor will not run or smells burnt
- You find wiring problems or a tripped breaker that keeps tripping
- The unit is heavily rusted or leaking into the roof
- Repairs keep adding up. Ask about conversion.
Frequently asked questions
Why is my swamp cooler blowing warm air?
Common causes are dry or mineral-caked pads, a pump that is not moving water, no water supply, or high humidity. Check these before calling for service.
Why does my swamp cooler smell musty?
Pads that stay wet or need replacing are a common cause. Clean the pan and replace old pads.
Why is airflow weak?
A slipping belt, a failing motor, clogged pads, or closed vents can all reduce airflow. Make sure a window or relief vent is open.