How to Replace an Evaporative or Swamp Cooler Pump

Symptoms of a Failing Water Pump

• Reduced or no water flow to cooling pads
• Unusual noise or vibration from the pump area
• Water leakage around the pump housing
• Pump runs but water doesn’t circulate
• Intermittent operation

Confirm the Replacement Pump Size First

Before removal, record the old pump’s voltage, frequency, flow rate, maximum head, outlet size and mounting dimensions. A replacement pump should use the same supply voltage and connection type, with enough head height to lift water from the sump to the top distribution tube. Do not substitute a purge pump for the main circulation pump: they perform different jobs.

Step-by-Step Replacement

1. Access the Pump

Remove the service panel or access cover on the side or bottom of your cooler. The pump is typically located in the water sump/tank area at the bottom of the unit.

2. Disconnect Plumbing

Disconnect the water outlet hose or pipe from the pump. Note the connection type — threaded, push-fit, or hose barb. If threaded, unscrew carefully to avoid damaging the threads.

3. Remove the Old Pump

Unplug the electrical connector from the pump. Remove any mounting screws or brackets. Lift the old pump out of the sump. Check for debris or scale buildup in the sump area.

4. Install the New Pump

Position the new pump in the sump. Secure with the original mounting method. Reconnect the water outlet — ensure a tight seal to prevent leaks. Plug in the electrical connector.

5. Test

Refill the water tank to the proper level. Reconnect power and run the pump. Check for proper water flow to the cooling pads and verify there are no leaks at the connections.