The Grundfos UPM3 FLEX 25-75 circulator pump delivers outstanding performance with energy-saving efficiency and flexible control options for modern heating systems. Designed to replace older generation circulators, this pump is suitable for central heating, underfloor heating, and hot water recirculation applications that demand reliability, quiet operation, and compact installation. It combines trusted Grundfos engineering with a flexible design that can be installed with or without external PWM control, helping future-proof your system integration.
🌟 Key Features
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A-rated efficiency: Meets strict eco-design requirements with high pump performance and low running costs.
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Flexible control: Can operate with or without external PWM speed control signals (profile A standard).
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Compact design: Smaller and easier to fit than traditional circulators, ideal for tight spaces.
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High reliability: Durable construction with ceramic bearing shaft and electronic de-blocking for dependable long-term service.
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Quiet & low-maintenance: Engineered for silent operation and minimal maintenance.
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Universal fit: Standard threaded connections for quick installation and replacement.
🧰 Technical Specifications
| Specification | Details |
|---|---|
| Model Name | Grundfos UPM3 FLEX 25-75 (130) |
| Pump Type | High-efficiency circulator |
| Connection Size | G 1½″ (≈ DN25) threaded |
| Port-to-Port Length | 130 mm standard |
| Maximum Head | Up to approx. 7.0 m (varies by curve/performance setting) |
| Liquid Temperature Range | ~2 °C to 110 °C operating range |
| Rated Voltage | 1×230 V ~ 50 Hz |
| Maximum Operating Pressure | 10 bar |
| Maximum Ambient Temperature | Up to ~70 °C |
| Energy Efficiency Index (EEI) | A-rated high efficiency |
| Protection Class | IP44 splash-proof |
| Pump Housing Material | Cast iron – robust and corrosion-resistant |
| Control Options | PWM profile A control or manual speed selection |
| Installation Orientation | Suitable for compact horizontal/vertical installs |
| Weight | ~1.8–1.9 kg (varies by exact variant) |
Note: Exact performance curves and settings depend on installation and control configuration — see the manufacturer’s datasheet for detailed flow vs head curves.
📈 Typical Applications
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Residential and commercial underfloor heating circuits
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Central heating circulation for boiler systems
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Hot water recirculation loops
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Hydronic HVAC systems
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Retrofit replacement for older circulators
💡 Why Choose the Grundfos UPM3 FLEX?
The UPM3 FLEX pump from Grundfos sets a benchmark for versatility and efficiency in circulation technology. Its ability to operate with external control signals or stand-alone makes it ideal for both OEM and retrofit installations — providing energy savings, adaptability, and quiet performance. Whether you’re installing a new system or upgrading an older one, the UPM3 FLEX offers a smart balance of power, efficiency and compact design.