Product Description

Grundfos Amazon Universal 1.5 Bar Twin Negative Pump

Model: 96787503 / STN-1.5 B

The Grundfos Amazon STN-1.5 B Universal 1.5 Bar Twin Negative Head Shower Pump is a premium automatic twin impeller shower booster pump designed specifically for negative head plumbing systems where the cold water storage tank is positioned below the shower outlet. In these installations, a specialist negative head pump is required to detect water demand automatically and provide reliable water pressure, even when natural gravity flow is unavailable.

Part of the renowned Grundfos Amazon range, the STN-1.5 B is widely recognised as the “Rolls Royce” of shower pumps. Manufactured using heavy-duty brass impellers and precision-machined brass components, it delivers exceptional durability, quiet operation and dependable long-term performance.

Designed to boost both hot and cold water supplies simultaneously, the STN-1.5 B provides a consistent 1.5 bar pressure increase, making it ideal for improving shower performance in gravity-fed negative head systems. Intelligent automatic controls, premium centrifugal technology and anti-vibration feet ensure smooth, reliable operation every day.

Grundfos Amazon STN-1.5 B Features

• Universal Twin Negative Head Shower Pump
• Model: STN-1.5 B
• Part Number: 96787503
• 1.5 Bar Pressure Rating
• Suitable for Negative Head Systems
• Twin Impeller Design
• Boosts Both Hot & Cold Water Supplies
• Heavy Duty Brass Impellers
• Precision Machined Brass Internal Components
• 230 Volt Power Supply
• 22mm Connections
• Centrifugal Pump Design
• Built-in Automatic Flow Switch
• Built-in Automatic Pressure Switch
• Anti-Vibration Feet
• Supplied with Flexible Hoses
• WRAS Approved
• CE Compliant
• 5 Year Manufacturer Warranty
• Grundfos Amazon Installation Guide
• Grundfos Amazon Pump Brochure

Key Features & Benefits

• Automatic Negative Head Operation – Designed specifically for systems where the cold water storage tank is below the shower outlet.
• Reliable 1.5 Bar Performance – Improves shower pressure while maintaining smooth and balanced water flow.
• Twin Impeller Design – Simultaneously boosts both hot and cold water supplies for consistent performance.
• Heavy Duty Brass Construction – Premium brass impellers and machined brass components provide exceptional durability.
• Automatic Flow Detection – Integrated flow switch starts the pump automatically whenever water demand is detected.
• Automatic Pressure Control – Pressure switch maintains system pressure and automatically stops the pump after use.
• Quiet Smooth Operation – Anti-vibration feet minimise vibration and operational noise.
• 5 Year Manufacturer Warranty – Long-term manufacturer support for added peace of mind.

Technical Specification

• Model: STN-1.5 B
• Part Number: 96787503
• Brand: Grundfos
• Product Type: Universal Twin Shower Pump
• System Type: Negative Head
• Pressure Rating: 1.5 Bar
• Power Supply: 230 Volt
• Connections: 22mm
• Pump Type: Centrifugal
• Approvals: WRAS Approved & CE Compliant
• Warranty: 5 Years

What’s Included?

• 1 × Grundfos Amazon STN-1.5 B Universal Twin Shower Pump
• 4 × Manufacturer Supplied Flexible Hoses
• Built-in Anti-Vibration Feet
• Installation Instructions

Ideal For

• Negative head plumbing systems
• Gravity-fed shower systems
• Boosting both hot and cold water supplies
• Domestic shower installations
• Properties with low water pressure
• Replacement shower pumps
• Professional plumbing installations
• Homes where the cold water tank is below the shower outlet

Why Choose the Grundfos Amazon STN-1.5 B?

The Grundfos Amazon STN-1.5 B has been specifically developed for negative head plumbing systems where conventional positive head pumps cannot function correctly. Its intelligent automatic controls detect water demand without relying on gravity flow, ensuring dependable water pressure whenever it is needed.

Manufactured with premium brass components and backed by a comprehensive 5-year manufacturer warranty, the STN-1.5 B delivers the exceptional quality, durability and quiet operation that have made the Grundfos Amazon range a trusted choice among professional installers.

Why Buy from SNH Tradecentre?

• Competitive prices on Grundfos shower pumps
• Large stock availability
• Nationwide delivery available
• Expert plumbing and heating advice
• Trade and public customers welcome
• Trusted UK plumbing supplier
• Collection available from our Kent trade counter