If the pads are dry and the air is warm, the water isn’t reaching them. Check the water supply, the float valve, the pump and the line that feeds the pads, in that order. Most of that is a careful homeowner’s job. Wiring and a dead motor aren’t, and Climate Pros Tucson can match you with a licensed pro for those.

How do you tell a pump problem from a humidity problem?

Look at the pads. Wet across the face with the fan running means the water side is working, and weak cooling may be monsoon humidity. At Tucson’s airport, average dew points sit in the 20s most of the year and jump into the high 50s in July and August, so a cooler can feel weak then even when it’s fine. Dry or patchy pads mean the water isn’t getting there. See why your swamp cooler quits when the monsoon starts for the humidity side.

What can you check yourself?

Turn the power to the cooler off first, and shut the water supply before you reach into the sump. Then work through these.

  1. Water level. Is there water in the sump? If not, the supply line or float valve may be stuck or clogged.
  2. Float valve. The float should rise with the water and shut the supply. If it sticks or the arm is bent, water won’t refill correctly.
  3. Distribution line. A clogged tube or distribution tray leaves part of the pad dry.
  4. Pump. With the power off and the pump out of the water, check that the inlet screen isn’t blocked and the pump can turn freely.
  5. Scale. Tucson Water says hard water builds calcium deposits in evaporative coolers, and it advises regularly changing the pads and adding an in-line filter. Crust on the pump inlet or inside the distribution tubes can stop water from reaching the top of the pads. Hard water and bleed-off kits covers slowing it down.

Is it the pump or the motor?

The pump moves water. The blower motor moves air. If you hear the fan and the pads stay dry, suspect the pump or the water feed. If the water flows but no air moves, suspect the blower motor, belt or switch. Those are separate parts, and mixing them up costs time.

What is safe DIY and what needs a pro?

Cleaning pads, clearing a line and freeing a stuck float are reasonable for a careful homeowner on a stable roof. Anything that involves electrical wiring, a failed motor, or working near a roof edge is a job for a professional. A pump that’s clean, sitting in water and still won’t hum has a power or wiring question behind it, not a plumbing one. Ask whether the pro works on evaporative coolers, and check on roc.az.gov that the license covers evaporative cooling (R-39, or an R-39R evaporative cooling subclass).

When does it make sense to stop repairing?

Repeated pump failures, heavy scale and a roof opening that leaks can all add up to a unit that’s due for replacement. Some homeowners then choose refrigerated air. Swamp cooler vs AC in Tucson and replacing a swamp cooler with central air cover that choice, and AC installation is the service involved. The hub at HVAC service in Tucson lists where we cover.

When the water side isn’t the problem

Call when the pump, motor or wiring is past a simple fix, or when you’re ready to price refrigerated air. Call (520) 353-2520 and we’ll match you with a licensed local pro.