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Sold By The m²
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Free Samples
See the finish before you commit
Trade Account
Trade prices on every range
Expert Advice
Speak to our team · 020 4634 2203
Free Delivery
On orders over £300
Sold By The m²
Calculator on every tile and floor
Klarna & PayPal
Spread the cost, subject to status

Trade Prices
Always trade prices, never retail markup.
UK Delivery
£50 flat rate • up to 20 business days.
FENSA Fitting
Professional install available.
by Linx Square
SKU: WHS-M-S3-MIX
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Linx Square
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Linx Square
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Linx Square
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Linx Square
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The Warmup S3 Manifold Mixing Unit is essential for managing heat sources where the flow temperature may exceed the design water temperature of the floor heating system. This is particularly relevant for heat sources that might overheat during sterilisation cycles or uncontrolled heating.Featuring true 3-way mixing control, the Warmup S3 Mixing Unit blends heated water from the primary heating circuit with water from the secondary floor circuits through the manifold. The unit includes an adjustable primary bypass to ensure a minimum flow rate is maintained for any heat source, such as heat pumps. This facilitates the easy commissioning of primary circuits before the underfloor heating (UFH) system is operational. Additionally, it features an adjustable secondary bypass.The unit is equipped with the Grundfos UPM3 25-70 130 circulator, known for its high efficiency and compliance with EcoDesign requirements. This circulator utilizes a neodymium permanent magnet and a 3-phase ECM stator with six windings. In Constant Pressure Mode, the circulator ensures a constant flow rate through each active circuit, regardless of the number of circuits.For added convenience, the mixing unit includes a circulator isolation valve. This valve prevents water from bypassing circuits during manifold filling and minimizes water loss during circulator replacement, all without introducing additional flow resistance or noise like check valves.Temperature control is managed by a capillary actuator, allowing adjustable set points between 20°C and 60°C. This meets the EN1264:4 requirements for 25°C screed commissioning. The actuator features a tamper-resistant adjustable head, which restricts temperature adjustments to a preset limit or locks it in place for security.