Topic
Troubleshooting
Start from what you can see, hear or smell. Each guide walks the checks in the order technicians use them: the quickest and most likely causes first, the expensive parts last.
Start here
Swamp Cooler Not Cooling: A Step-by-Step DiagnosisA swamp cooler that runs but does not cool usually has one of four problems: pads that are not fully wet (pump, float or distributor fault), no relief air because windows are closed, outdoor humidity too high for evaporation, or scaled, clogged pads. Check pad wetness and open a window first; those two fix most cases.
Symptom finder
| What you notice | Check first | Then check | Full guide |
|---|---|---|---|
| Air blows but is not cold | Pads dry or partly dry (pump, distributor, water level) | Outdoor humidity, no relief air, worn pads | Not cooling |
| Pads stay dry, motor runs | Pump switch and pump cord, low water | Clogged pump intake or distributor, failed pump | Pump not working |
| Musty, fishy or swampy smell | Stagnant water, algae in the pan | Old pads, overheating motor or pump (fishy can mean electrical) | Smells |
| Water dripping or overflowing | Float valve set too high or stuck | Overflow fitting, rusted pan, clogged trough | Leaking |
| House feels damp or sticky | Not enough open windows or relief vents | Humid outdoor weather (monsoon) | Too humid |
| Squealing, rattling or grinding | Belt tension and alignment | Dry or worn bearings, loose blower wheel | Noises |
| Motor hums or does nothing | Breaker, disconnect, control switch | Seized bearings, thermal overload, failed motor | Motor not running |
Before you touch anything: switch the cooler off at the control, then turn off power at the disconnect switch beside the unit or at the breaker. Water and line voltage share the same cabinet.
All troubleshooting guides
- Why Your Swamp Cooler Smells (and How to Get Rid of Each Odor)
Musty, fishy, rotten egg or burning smell from your swamp cooler? Match the odor to its cause, from stagnant pan water to new pads or a hot motor, and fix it.
- Swamp Cooler Leaking: How to Find the Source and Stop It
Swamp cooler leaking on the roof, into the ceiling or out of the registers? Trace overflowing floats, rusted pans, clogged drains and overspray, easiest first.
- Swamp Cooler Pump Not Working: Diagnosis and Fixes
Swamp cooler pump not pumping water to the pads? Check power, water level, clogged intake, seized impeller and distributor lines in order, plus when to replace.
- Swamp Cooler Making the House Too Humid: What to Check and Fix
House feels sticky with the swamp cooler on? Learn why: too little relief air, low fan speed, humid weather or pad carryover, and how to bring humidity down.
- Swamp Cooler Noises: What Each Sound Means and How to Fix It
Squealing, grinding, rattling, thumping or humming from your swamp cooler? Match the sound to belt, bearing, blower, pump or panel problems and fix it in order.
- Swamp Cooler Motor Not Running: Step-by-Step Troubleshooting
Swamp cooler fan motor won't start, hums, or shuts off after a few minutes? Check power, switch, thermal overload, capacitor, bearings and belt in a safe order.