1. Introdución
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. Información de seguridade
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.
- Seguridade eléctrica: 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.
- Seguridade da presión: The maximum working pressure for this pump is 145 PSI. Do not exceed this pressure.
- Seguridade de temperatura: The pump is designed for a temperature range of 14°F to 230°F. Ensure system temperatures remain within this range.
- Instalación: The pump can be installed in any position where the shaft is horizontal. Improper installation can lead to malfunction or damage.
- Xeral: Do not operate the pump dry. Ensure the system is filled with fluid before starting.
3. Produto rematadoview
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.

Compoñentes clave:
- Carcasa da bomba: Green-colored body, typically bronze volute.
- Motor: Wet rotor design, 115-Volt, 60Hz.
- Interruptor selector de velocidade: 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. Configuración e instalación
Unha instalación axeitada é crucial para o rendemento e a lonxevidade da bomba.
- Preparación do sistema: Ensure the heating or cooling system is drained and clean before installation.
- Posición de montaxe: 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.
- Conexións de tubos: 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.
- Cableado eléctrico:
- 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.
- Recheo do sistema: 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. Instrucións de funcionamento
The Wilo Star S 21F pump offers three selectable speeds to match system requirements.
- Encendido: Once the pump is installed and the system is filled, restore power to the circuit.
- Selección de velocidade: 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.
- Velocidade 2: Medium power consumption (77W), for moderate flow.
- Speed 3 (Max): Highest power consumption (98W), for maximum flow and head.
- Seguimento: Observe the system for proper circulation and listen for any unusual noises.
6. Mantemento
The Wilo Star S 21F is designed for minimal maintenance. However, periodic checks can ensure optimal performance and extend its lifespan.
- Inspección anual: Annually inspect the pump for any signs of leaks, corrosion, or unusual wear.
- Calidade do fluído do sistema: Ensure the system fluid is clean and free of debris. Contaminants can reduce pump efficiency and lifespan.
- Conexións eléctricas: Periodically check electrical connections for tightness and signs of overheating. Disconnect power before checking.
- Purga de aire: If the pump becomes noisy, it may indicate air in the system. Follow system-specific procedures to purge air.
7 Solución de problemas
Consulta a táboa seguinte para ver os problemas comúns e as súas posibles solucións.
| Problema | Causa posible | Solución |
|---|---|---|
| A bomba non arranca | No power; faulty wiring; seized impeller | Check power supply and circuit breaker. Verify electrical connections. Consult a qualified technician if impeller is seized. |
| A bomba é ruidosa | Air in system; cavitation; foreign object in pump | Purge air from the system. Check system pressure. Inspect pump for obstructions (disconnect power first). |
| Caudal insuficiente | Incorrect speed setting; air in system; clogged filter; undersized pump | Increase speed setting. Purge air. Check and clean system filters. Verify pump sizing for application. |
| A bomba está perdendo | Loose connections; damaged gaskets; cracked housing | Tighten flange connections. Replace damaged gaskets. If housing is cracked, pump replacement may be necessary. |
8. Especificacións
| Especificación | Valor |
|---|---|
| Marca | Wilo |
| Número de modelo | 4105032 (Typ Star S 21 FX) |
| Voltage | 115 voltios |
| Frecuencia | 60 Hz |
| Maximum Current (I max) | 0.70 A |
| Consumo de enerxía (W) | Speed 3: 98W, Speed 2: 77W, Speed 1: 55W |
| Caudal máximo | 21 galóns por minuto |
| Altura máxima de elevación (cabeza) | 21 pés |
| Rango de temperatura | 14 °F a 230 °F (-10 °C a 110 °C) |
| Presión máxima de traballo | 145 PSI |
| Material | Stainless Steel (shaft), Bronze (volute) |
| Peso do elemento | 7.08 libras (3.22 kg) |
| Tamaño da brida | 3/4-Inch - 1-1/2-Inch standard flange |
| Clase de recinto | CSA enclosure 2 |
| Clase de illamento | Clase F |
9. Garantía e soporte
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.





