Evaporative Cooler Leaking Water? Common Causes and Fixes

A leaking cooler wastes water and, in the worst case, can stain or damage the ceiling below. Most leaks come from one of a few places, and many are cheap to fix. Turn off the water supply to the cooler first if water is getting inside the house.

1. Water running from the overflow or drain

If water runs constantly from the overflow or drain pipe while the cooler is on, the tray is overfilling or the drain valve isn’t sealing. Check the float valve or water sensor, the inlet solenoid and the drain or dump valve. See cooler overflowing or water running constantly.

2. Dripping when the cooler is off

Water dripping with the cooler off usually means the inlet solenoid isn’t closing fully, so water keeps trickling in. Solenoids wear and collect grit over time. See our solenoid valve guide and solenoid valves.

3. Leaking fittings or hoses

Check the water supply line, the fittings at the solenoid and float valve, and the pump hose and distributor. Old fittings and hoses crack in the sun. Tighten or replace them as needed.

4. Water blowing out of the pads

If water sprays off the outside of the pads, the pads may be damaged or fitted wrongly, or the pump may be pushing too much water for the pads. Check the pads are seated properly and not crumbling. See our pads guide.

5. Blocked overflow or drain line

A blocked overflow can make water spill over the tray edge. Clear the drain line of leaves and scale.

6. Water coming through the ceiling vent

Water dripping from the ceiling outlet often points to a leak inside the cooler or duct, an overfilled tray, or a damaged duct seal. Turn the cooler off and have it inspected promptly.

7. Cracked tray or cabinet

Old plastic or metal trays can crack or rust through. Some can be sealed, but a badly damaged tray may mean replacing the cooler.

Find the faulty part

Browse solenoid valves, float valves and drain and dump valves, or send us your cooler model and a description of the leak and we’ll help you find the right part.

Popular replacement parts

• Seeley Breezair / Braemar 24VAC Solenoid Valve #638638 Long Lead (638638)
• Bonaire Solenoid Valve 24V 15mm With Dump/Bleed (6051636SP)
• OEM Brivis 1/2″ Solenoid Valve 24VAC with Bleed (B016314)
• Breezair / Braemar / Coolair Vertical Float Valve (901114)
• Brivis Philmac Float Valve Assembly with Float (B000414)
• Bonaire Cistern Float Ball Valve (6050916SP)
• Breezair / Braemar Drain Valve and Shutoff 24VAC (105345)
• Bonaire Aquamiser Valve Seal MK2 (6050197SP)

This guide is general information only. Always follow your cooler manufacturer’s instructions, and use a licensed electrician for any electrical work.