Product Description

OSO Super Xpress S2X 250L Direct Unvented Cylinder

Model: S2X250 | Product Number: 11011689

Enjoy fast installation and a generous supply of mains-pressure hot water with the OSO Super Xpress S2X 250L Direct Unvented Cylinder. OSO supplies this electric cylinder pre-plumbed and pre-wired. Therefore, it can save valuable time during installation.

The S2X250 uses two 3kW titanium immersion heaters to heat the stored water. As a direct cylinder, it does not need a boiler or primary heating coil. This makes it a practical choice for compatible homes and properties that use electricity to produce hot water.

OSO houses the expansion vessels, valves, pipework and electrical connections beneath a removable top cover. As a result, the finished installation looks clean while the main components remain accessible for servicing.

The model has a nominal size of 250 litres and a tested vessel capacity of 254 litres. Its body measures 595mm in diameter and 1645mm high. It also includes a secondary-return connection for a compatible pumped hot water circulation system.

OSO Super Xpress S2X 250L Features

• Direct electric unvented hot water cylinder
• Fully pre-plumbed and pre-wired design
• Two 3kW titanium immersion heaters
• Total connected heating capacity: 3kW + 3kW
• Nominal size: 250 litres
• Tested vessel capacity: 254 litres
• Mains-pressure hot water supply
• Integral expansion vessels
• Factory-fitted safety and control valves
• Factory-fitted hot water blending valve
• Secondary-return connection
• Concealed pipework and cable routing
• Top connections hidden beneath a removable lid
• High-grade PUR foam insulation
• Stainless-steel cylinder construction
• Compact 595mm diameter footprint
• Energy efficiency rating: C
• Standing heat loss: approximately 1.85kWh per 24 hours
• 25-year cylinder warranty, subject to OSO terms
• Model: S2X250
• Product number: 11011689

OSO S2X250 Specification

• View the OSO Super Xpress S2X Product Information
• Download the OSO S2X Technical Data Sheet
• Download the OSO Super Xpress S2X Installation Manual
• Brand: OSO Hotwater
• Range: Super Xpress S2X
• Model: S2X250
• Product type: direct unvented hot water cylinder
• Nominal capacity: 250 litres
• Actual vessel capacity: 254 litres
• Usable hot water above 40°C: up to 464 litres under the manufacturer’s test conditions
• Heating method: electric immersion heaters
• Immersion-heater output: 3kW + 3kW at 240V
• Electrical supply: 220-240V, 50Hz
• Immersion-heater material: Grade 1 titanium
• Number of immersion heaters: two
• Height: 1645mm
• Diameter: 595mm
• Empty weight: 50kg
• Filled weight: approximately 304kg
• Insulation: high-grade PUR foam
• Average insulation thickness: 95mm
• Energy efficiency rating: C
• Load profile: XL
• Standing heat loss: 77 watts
• Standing heat loss per 24 hours: approximately 1.85kWh
• Operating pressure: 3 bar
• Maximum design pressure: 10 bar
• Maximum operating temperature: 75°C
• Expansion-vessel capacity: 2 x 8 litres
• Secondary return: 15mm connection
• Ingress protection: IP21
• Product number: 11011689
• GTIN: 7070644010775

What Is Included?

• 1 x OSO Super Xpress S2X 250 direct unvented cylinder
• 2 x Factory-fitted 3kW titanium immersion heaters
• 2 x Integral 8-litre expansion vessels
• Factory-fitted pressure-reducing valve
• Factory-fitted expansion-relief valve
• Factory-fitted temperature and pressure relief valve
• Factory-fitted hot water blending valve
• Factory-fitted tundish
• Pre-fitted internal pipework and flexible connections
• Pre-wired electrical connections
• Secondary-return connection
• Removable top cover
• First-fix installation template

Always check the current OSO packing list and installation manual when the cylinder arrives.

Why Choose a Direct Unvented Cylinder?

A direct cylinder uses electric immersion heaters to heat the stored water. Therefore, it does not rely on a gas boiler, oil boiler or primary heating coil.

The unvented design connects to the incoming mains water supply. As a result, it can supply mains-pressure hot water to compatible taps and showers without a cold-water storage tank in the loft.

However, the available flow rate depends on the incoming mains water pressure, available flow and pipework design. Your installer should test the water supply before choosing the cylinder.

Two Titanium Immersion Heaters

The OSO S2X250 has two 3kW titanium immersion heaters. The lower heater can heat the main stored volume. Meanwhile, the upper heater can heat a smaller quantity of water when a faster boost is needed.

The twin-immersion arrangement can also support compatible off-peak or timed electricity systems. However, an electrician must confirm the required circuits, controls and electricity-tariff arrangement.

Titanium provides strong resistance to corrosion. Therefore, it suits demanding use and hard-water areas when the cylinder receives the correct installation and maintenance.

Pre-Plumbed and Pre-Wired Design

OSO installs the main valves, expansion equipment, electrical connections and internal pipework at the factory. Therefore, the installer has fewer separate components to position and connect on site.

OSO states that the S2X design can save several hours of labour during a typical installation. In addition, the included first-fix template allows work to begin before the cylinder arrives on site.

Once installed, the removable lid hides the main pipework and valve gear. This provides a clean finish while keeping the components accessible for servicing.

High Hot Water Output

OSO stores the water at a high temperature and uses the factory-fitted blending valve to mix it with cold water at the outlet. This design allows the cylinder to deliver more usable hot water than its stored vessel capacity alone may suggest.

Under the manufacturer’s stated test conditions, the S2X250 can provide up to 464 litres of mixed hot water above 40°C. Actual performance will vary with the incoming water temperature, thermostat setting, flow rate and blending-valve setup.

The installer must commission the blending valve and confirm safe water temperatures throughout the property.

Secondary Hot Water Return

The S2X250 includes a secondary-return connection. This connection can form part of a correctly designed pumped hot water circulation system.

A secondary-return system can reduce the time it takes for hot water to reach distant outlets. However, it can also increase heat loss and energy use. Therefore, a competent installer must size, control and insulate the circulation pipework correctly.

OSO S2X250 Dimensions

• Overall height: 1645mm
• Overall diameter: 595mm
• Empty weight: 50kg
• Approximate filled weight: 304kg

Allow extra space above and around the cylinder for pipework, discharge connections, electrical wiring, servicing and removal of the top cover. Always use the current OSO technical drawing when planning the cupboard.

Installation Requirements

• Installation must comply with Building Regulations Approved Document G3
• A qualified and competent unvented-cylinder installer must complete the work
• A qualified electrician must complete the electrical connections
• The installer must test the incoming water pressure and flow rate
• The supporting floor must carry the full operating weight
• The safety-valve discharge pipework must follow current regulations
• The tundish must remain visible after installation
• The installer must provide suitable servicing access
• The cylinder must remain upright during installation and operation
• All electrical work must follow current IET Wiring Regulations
• The installer must commission the complete system before use
• Follow the current OSO installation manual in full

This is an unvented hot water cylinder. Therefore, it must not be installed as a general DIY product.

Check Before Ordering

• Confirm that a 250-litre cylinder suits the property and expected demand
• Check that a direct electric cylinder matches the heating design
• Confirm the electrical supply for two 3kW immersion heaters
• Measure the installation space and access route
• Allow room above the cylinder to remove the top cover
• Check the incoming mains pressure and flow rate
• Plan a compliant route for the safety discharge pipework
• Confirm whether the installation requires a secondary-return system
• Ask the installer to approve the product before ordering

OSO Super Xpress Warranty

OSO offers a 25-year warranty on the cylinder, subject to its current terms and conditions. Separate warranty periods may apply to immersion heaters, valves, controls and other components.

Correct installation, commissioning, servicing and product registration may affect warranty cover. Therefore, keep your invoice, commissioning records and service history. You should also follow OSO’s current warranty requirements.

Why Buy from SNH Tradecentre?

SNH Tradecentre supplies unvented hot water cylinders and installation components to homeowners, landlords, developers and professional installers across the UK.

Our experienced team can help you check the cylinder type, dimensions and basic specification before you order. We can also help identify the additional fittings that your installation may require.

If you need advice about the OSO Super Xpress S2X250, call us on 01843 842727 or visit our trade counter in Birchington, Kent.