1. Introduction
This manual provides essential information for the safe and efficient operation of your Wilo Varios PICO-STG 15/1-8 high-efficiency pump. This pump is specifically designed for use in heating, cooling, industrial, solar, and geothermal installations, offering reliable performance and energy efficiency.
2. Safety Instructions
Please read and understand all safety instructions before installing, operating, or maintaining the pump. Failure to follow these instructions may result in personal injury, property damage, or pump malfunction.
- Electrical Safety: Always disconnect the power supply before performing any installation, maintenance, or repair work on the pump. Ensure all electrical connections are made by a qualified electrician and comply with local regulations.
- Qualified Personnel: Installation and complex maintenance should only be performed by qualified and authorized personnel.
- Hot Surfaces: The pump and connected pipes may become hot during operation. Allow them to cool before handling.
- System Pressure: Ensure the system pressure is released before opening any connections or performing maintenance.
- Intended Use: Use the pump only for its intended purpose as described in this manual.
3. Components Overview
The Wilo Varios PICO-STG 15/1-8 pump features a robust design with user-friendly controls and advanced technology.

Figure 3.1: Front view of the Wilo Varios PICO-STG 15/1-8 pump, showing the control panel with LED indicators and push buttons, and the green pump housing.
Key components and features include:
- Pump Body: Constructed from grey cast iron with KTL coating for durability.
- Control Panel: Features 'Green button technology' with push buttons for regulation and setting, and an LED display for operational status and error codes.
- Motor: Blockage-resistant synchronous motor utilizing ECM technology for high efficiency.
- Connections: Double electrical connector (Molex and Wilo type) and an iPWM connector for external control.
- Integrated Electronic Power Control: For continuous differential pressure control.
4. Setup and Installation
The Wilo Varios PICO-STG 15/1-8 pump is designed for easy integration into various systems. Ensure proper planning and adherence to technical specifications during installation.

Figure 4.1: Technical drawing of the Wilo Varios PICO-STG 15/1-8 pump, illustrating its dimensions including length (130mm) and connection sizes (G).
4.1 Mechanical Installation
- Mounting Position: Install the pump in a suitable location, ensuring adequate space for ventilation and future maintenance. The pump can be installed horizontally or vertically.
- Pipe Connections: The pump features DN 25 (1") external threads. Ensure clean and secure connections to the system piping. The pump has a length of 130 mm.
- System Filling: After installation, fill the system with the appropriate medium and purge any air. The pump has a built-in purge function.
4.2 Electrical Connection
- Power Supply: Connect the pump to a 230 V, 50/60 Hz power supply. Use the provided 3-pin pump plug and Wilo connector.
- PWM Signal: The pump can operate with or without an external PWM signal. If using PWM control, connect the iPWM connector accordingly.
- Grounding: Ensure the pump is properly grounded to prevent electrical hazards.
5. Operating Instructions
The Wilo Varios PICO-STG 15/1-8 pump is designed for intuitive operation using its 'Green button technology' and LED display.
- Power On/Off: Once connected to the power supply, the pump will initiate its startup sequence.
- Regulation Control: Use the push button for control regulation to select the desired operating mode (e.g., constant differential pressure, variable differential pressure).
- Setting Adjustment: Use the push button for setting to adjust specific parameters within the selected operating mode.
- LED Display: The LED display provides visual feedback on the pump's current status, selected operating mode, and any error codes.
- Manual Programming Mode: The pump includes a synchronization function for manual programming, allowing for precise control over its operation.
- External Control: The pump supports various external control types via its iPWM connection.
- Purge Function: Activate the purge function to automatically vent air from the pump and system, ensuring optimal performance.
- Manual Reset: In case of a malfunction or error, a manual reset function is available to restart the pump.
6. Maintenance
The Wilo Varios PICO-STG 15/1-8 is designed as a maintenance-free circulation pump. However, regular checks can help ensure its longevity and optimal performance.
- Visual Inspection: Periodically inspect the pump and connections for any signs of leaks, corrosion, or damage.
- Particle Filter: The pump is equipped with a particle filter. While generally maintenance-free, in systems with high particulate matter, occasional inspection and cleaning of the filter may be beneficial to prevent blockages and maintain efficiency.
- System Medium: Ensure the system medium is clean and free of debris that could affect pump operation.
- Electrical Connections: Verify that all electrical connections remain secure and free from corrosion.
For any complex maintenance or repairs, always consult a qualified service technician.
7. Troubleshooting
This section provides guidance on common issues you might encounter with your Wilo Varios PICO-STG 15/1-8 pump. The LED display will often show error codes to assist in diagnosis.
| Problem | Possible Cause | Solution |
|---|---|---|
| Pump does not start | No power supply; Incorrect wiring; Motor blockage. | Check power connection and circuit breaker; Verify wiring according to diagram; Perform manual reset; Check for blockages. |
| Reduced flow/pressure | Air in system; Clogged particle filter; Incorrect settings. | Activate purge function; Inspect and clean particle filter; Adjust pump settings via control panel. |
| Unusual noise/vibration | Air in pump; Foreign objects in pump; Improper mounting. | Activate purge function; Disconnect power and inspect pump for foreign objects (if safe to do so); Ensure pump is securely mounted. |
| Error code displayed | Specific malfunction detected by the pump's internal diagnostics. | Refer to the pump's LED display for the specific error code. Consult the Wilo technical documentation or contact customer support with the error code for detailed troubleshooting steps. Try a manual reset. |
If the problem persists after attempting these solutions, or if you encounter an issue not listed here, please contact Wilo customer support or a qualified service technician.
8. Specifications
Technical data for the Wilo Varios PICO-STG 15/1-8 high-efficiency pump:
| Attribute | Value |
|---|---|
| Manufacturer | Wilo |
| Model Number | 4232742 |
| Product Dimensions (L x W x H) | 14 x 14 x 9.4 cm |
| Weight | 2 Kilograms |
| Item Quantity | 1 |
| Batteries Required | No |
| Media Temperature (Heating/Geothermal) | -20 °C to +95 °C |
| Media Temperature (Solar) | -10 °C to +110 °C |
| Operating Voltage | 230 V, 50/60 Hz |
| Energy Efficiency Index (EEI) | <0.20 |
| Power Consumption | 1-75 W |
| Protection Rating | IPX4D |
| Pump Body Material | Grey cast iron (KTL coating) |
| Length | 130 mm |
| External Thread | DN 25 (1") |
| Type | 15/1-8 |
| Nominal Dimensions | DN 15 (1/2") |
9. Warranty and Support
For detailed warranty information, technical support, and service inquiries regarding your Wilo Varios PICO-STG 15/1-8 pump, please refer to the official Wilo website or contact Wilo customer service directly. Keep your purchase receipt as proof of purchase for warranty claims.
Information regarding the availability of spare parts for this product is currently unavailable.





