Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of your Dial MC8500UL High-Efficiency Evaporative Cooler Pump. This pump is designed to circulate water in evaporative coolers with CFM ratings ranging from 4,000 to 8,500. It features a robust 115V motor, thermal overload protection for enhanced safety and longevity, and is engineered for quiet performance. The premium design includes a corrosion-resistant shaft and bearings, ensuring reliable and consistent operation. Please read this manual thoroughly before use.
Safety Information
Adherence to the following safety precautions is crucial for preventing personal injury and damage to the pump or evaporative cooler system.
- Electrical Hazard: Always disconnect power to the evaporative cooler before installing, servicing, or performing any maintenance on the pump.
- Grounding: Ensure the pump is properly grounded according to local electrical codes. The pump is equipped with a 3-prong grounded plug for your safety. Do not remove the grounding prong.
- Water Immersion: This pump is designed for continuous immersion in water. Do not operate the pump dry, as this can cause severe damage and void the warranty.
- Temperature Limits: Do not use this pump with liquids hotter than 120°F (49°C).
- Clearance: Keep hands, hair, and clothing clear of moving parts during operation.
- Intended Use: Use this pump only for its intended purpose in evaporative cooling systems. Do not use for pumping flammable liquids or in hazardous locations.
- Thermal Overload Protection: The pump is equipped with thermal overload protection. If the pump overheats, it will automatically shut off. Allow it to cool down before attempting to restart. Investigate the cause of overheating.
Product Overview

Figure 1: Dial MC8500UL High-Efficiency Evaporative Cooler Pump. The pump is blue, with a label indicating 'POWERCOOL EVAPORATIVE COOLER PUMP MODEL MC8500UL' and 'FOR COOLERS WITH CFM RATINGS FROM 4,000-8,500'. It has a 115V power cord with a standard plug. Alongside the pump are a metal mounting bracket and a mesh filter bag containing small components, likely for installation.
The Dial MC8500UL pump is a submersible unit designed for reliable water circulation in evaporative coolers. Key components include:
- Motor Housing: Contains the 115V motor with thermal overload protection.
- Impeller: Circulates water efficiently.
- Discharge Outlet: Connects to the water distribution system of the cooler.
- Power Cord: 115V, grounded plug.
- Mounting Brackets: Included for secure installation within the cooler's reservoir.
- Mesh Filter Bag: Helps prevent debris from entering the pump, extending its lifespan.
Setup and Installation
Before beginning installation, ensure the evaporative cooler is disconnected from all power sources.
- Prepare the Cooler: Drain any existing water from the evaporative cooler's reservoir and clean it thoroughly to remove sediment or debris.
- Mount the Pump:
- Position the pump in the cooler's reservoir, ensuring it sits level and is fully submerged when the cooler is filled with water.
- Use the included durable mounting brackets to secure the pump to the bottom or side of the reservoir, preventing movement during operation.
- Connect Water Line: Attach the cooler's water distribution hose to the pump's discharge outlet. Ensure a secure, leak-free connection.
- Install Filter Bag: Place the mesh filter bag over the pump's intake area or around the pump itself to prevent larger debris from entering and clogging the pump.
- Electrical Connection: Route the pump's power cord safely, avoiding pinch points or areas where it could be damaged. Plug the pump into a properly grounded 115V electrical outlet. Ensure the outlet is protected by a Ground Fault Circuit Interrupter (GFCI) if required by local codes.
- Fill Cooler: Fill the evaporative cooler's reservoir with water to the recommended operating level. Ensure the pump is fully submerged.
Operating Instructions
Once installed and the cooler is filled with water, the pump is ready for operation.
- Initial Start-up: Turn on the power to the evaporative cooler. The pump should begin circulating water to the distribution system, wetting the cooler pads.
- Check Water Flow: Verify that water is evenly distributed over the cooler pads. Adjust any distribution lines or nozzles as necessary to ensure optimal wetting.
- Monitor Water Level: Regularly check the water level in the cooler's reservoir. The pump must remain fully submerged during operation. Refill the reservoir as needed or ensure the automatic fill system is functioning correctly.
- Quiet Operation: The pump is engineered for low noise. Any unusual noises may indicate an issue requiring investigation (e.g., debris in the impeller, low water level).
Maintenance
Regular maintenance ensures the longevity and efficient performance of your pump.
- Weekly/Bi-Weekly:
- Disconnect Power: Always turn off and disconnect power to the cooler before performing any maintenance.
- Clean Filter Bag: Remove and clean the mesh filter bag to remove accumulated debris. Rinse it thoroughly and re-install.
- Inspect Pump: Visually inspect the pump for any signs of wear or damage. Check for debris around the impeller.
- Monthly/Seasonally:
- Clean Reservoir: Drain and thoroughly clean the evaporative cooler's water reservoir to prevent algae and mineral buildup.
- Inspect Impeller: If water flow is reduced, carefully remove any debris that may have bypassed the filter and lodged in the impeller area.
- Check Connections: Ensure all hose and electrical connections are secure and free from corrosion.
- End of Season (Winterization):
- Disconnect power and drain the cooler completely.
- Remove the pump from the reservoir. Clean it thoroughly and store it in a dry, frost-free location to prevent damage from freezing water.
Troubleshooting
Before troubleshooting, always disconnect power to the evaporative cooler.
| Problem | Possible Cause | Solution |
|---|---|---|
| Pump does not run. |
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| Low or no water flow. |
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| Pump is noisy. |
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Specifications
| Feature | Detail |
|---|---|
| Brand | Dial |
| Model Number | MC8500UL (Part No. 1442) |
| Voltage | 115 Volts |
| Power Source | AC |
| CFM Rating Compatibility | 4,000 - 8,500 CFM Units |
| Item Weight | 2 Pounds |
| Product Dimensions (L x W x H) | 4.5" x 4.5" x 8.5" |
| Material | Polyvinyl chloride or Polypropylene |
| Color | Black (Pump body is blue, but product listing specifies black) |
| Style | Diaphragm |
| UPC | 026529144209 |
| Manufacturer | Standard Plumbing Supply |
Warranty and Support
For specific warranty information regarding your Dial MC8500UL Evaporative Cooler Pump, please refer to the documentation included with your purchase or contact the retailer where the product was acquired. Warranty terms typically cover manufacturing defects for a specified period from the date of purchase.
For technical support, replacement parts, or further assistance, please contact the manufacturer, Standard Plumbing Supply, or your authorized Dial product dealer. Contact information can usually be found on the product packaging or the manufacturer's official website.





