Wilo 4105032 Star S 21F Three Speed Wet Rotor Hydronic Circulating Pump Instruction Manual

1. Introduction

This manual provides essential information for the safe and efficient installation, operation, and maintenance of the Wilo 4105032 Star S 21F Three Speed Wet Rotor Hydronic Circulating Pump. This pump is designed for use in hot-water heating systems, industrial circulation systems, cold-water systems, and air-conditioning systems. It is not approved for use with domestic hot water. The pump features a bronze volute and a wet rotor design.

2. Safety Information

Please read and understand all safety instructions before installing or operating the pump. Failure to follow these instructions may result in personal injury, property damage, or electric shock.

• Electrical Safety: Ensure the power supply is disconnected before any installation or maintenance work. All electrical connections must be performed by a qualified electrician in accordance with local and national electrical codes. The pump operates on 115-Volt, 60Hz power.
• Pressure Safety: The maximum working pressure for this pump is 145 PSI. Do not exceed this pressure.
• Temperature Safety: The pump is designed for a temperature range of 14°F to 230°F. Ensure system temperatures remain within this range.
• Installation: The pump can be installed in any position where the shaft is horizontal. Improper installation can lead to malfunction or damage.
• General: Do not operate the pump dry. Ensure the system is filled with fluid before starting.

3. Product Overview

The Wilo Star S 21F is a three-speed circulating pump designed for hydronic systems. It features a robust construction and a user-selectable speed setting to optimize performance and energy consumption.

Key Components:

• Pump Housing: Green-colored body, typically bronze volute.
• Motor: Wet rotor design, 115-Volt, 60Hz.
• Speed Selector Switch: Red rotary switch on the electrical box for selecting one of three speeds.
• Electrical Connection Box: Black enclosure for wiring connections.
• Flange Connections: Standard connections for system integration.

4. Setup and Installation

Proper installation is crucial for the pump's performance and longevity.

1. System Preparation: Ensure the heating or cooling system is drained and clean before installation.
2. Mounting Position: The pump can be installed in any position, provided the motor shaft remains horizontal. This is critical for proper lubrication and cooling of the wet rotor.
3. Pipe Connections: The pump uses 3/4-inch to 1-1/2-inch standard flanges. Use appropriate gaskets (typically supplied with the pump) and ensure a watertight seal. Avoid overtightening the flange bolts.
4. Electrical Wiring:
   • Disconnect power at the main breaker before beginning any wiring.
   • Open the electrical connection box.
   • The pump features quick and easy wire connectors. To insert wires, displace the white tabs 90 degrees to open the holes. Insert the stripped wires and then return the tabs to their original position to secure the connection.
   • Connect the pump to a dedicated 115-Volt, 60Hz circuit. Ensure proper grounding.
   • Close the electrical connection box securely.
5. System Filling: After installation, slowly fill the system with fluid, ensuring all air is purged from the pump and piping. Air in the system can cause noise and damage to the pump.

5. Operating Instructions

The Wilo Star S 21F pump offers three selectable speeds to match system requirements.

1. Power On: Once the pump is installed and the system is filled, restore power to the circuit.
2. Speed Selection: Locate the red rotary switch on the electrical connection box. This switch allows you to select one of three operating speeds:
   • Speed 1 (Eco): Lowest power consumption (55W), suitable for minimal flow requirements.
   • Speed 2: Medium power consumption (77W), for moderate flow.
   • Speed 3 (Max): Highest power consumption (98W), for maximum flow and head.
   Rotate the switch to the desired speed setting. The pump will begin operation at the selected speed.
3. Monitoring: Observe the system for proper circulation and listen for any unusual noises.

6. Maintenance

The Wilo Star S 21F is designed for minimal maintenance. However, periodic checks can ensure optimal performance and extend its lifespan.

• Annual Inspection: Annually inspect the pump for any signs of leaks, corrosion, or unusual wear.
• System Fluid Quality: Ensure the system fluid is clean and free of debris. Contaminants can reduce pump efficiency and lifespan.
• Electrical Connections: Periodically check electrical connections for tightness and signs of overheating. Disconnect power before checking.
• Air Purging: If the pump becomes noisy, it may indicate air in the system. Follow system-specific procedures to purge air.

7. Troubleshooting

Refer to the table below for common issues and their potential solutions.

8. Specifications

9. Warranty and Support

Wilo provides a 3-year limited warranty from the date of purchase for Residential Business Services products. For warranty claims, technical support, or further assistance, please contact Wilo customer service or your authorized dealer.