The Joule Invacyl Slimline Direct Unvented Cylinder (210L) is a high-capacity, space-saving stainless steel hot water cylinder designed for unvented systems. Its slim profile delivers mains-pressure hot water to multiple outlets while helping minimise the floor or plant-room space required. With durable construction, effective thermal insulation and a 210-litre capacity, it is well suited to larger homes, multi-occupancy properties and renovation projects where both capacity and available space are important.
2 × 3kW
Immersion Heaters
Key Features
210-Litre High Capacity
The 210-litre capacity is designed to support higher domestic hot-water demand across larger homes, multiple bathrooms and multi-occupancy properties.
Slimline Space-Saving Design
The slimline format provides substantial hot-water storage while helping reduce the floor or plant-room space required for installation.
LDX 2101 Stainless Steel
The cylinder is manufactured from LDX 2101 stainless steel for durable construction and long-term service.
Effective Thermal Insulation
Dense 50mm PU foam insulation helps retain stored heat, with a specified heat loss of 1.8 kWh over 24 hours.
Dual 3kW Immersion Heaters
Two 3kW immersion heaters operating at 230V provide the cylinder with electric heating capacity for hot-water recovery.
High-Pressure Performance
Designed for a maximum mains water pressure of 10 bar and an operating pressure of 7 bar, supporting reliable mains-pressure hot water delivery to multiple outlets.
Space-Efficient Hot Water Storage
The Joule Invacyl 210L combines a large hot-water storage capacity with a slimline design, making it suitable where higher hot-water demand needs to be accommodated without unnecessarily increasing the installation footprint.
Larger Properties Suitable for larger family homes and properties with multiple bathrooms.
Multiple Outlets
Provides mains-pressure hot water for properties with simultaneous hot-water demand.
Space-Conscious Installations
The slimline design is useful for renovation projects where available space is limited.
Durable Construction
LDX 2101 stainless steel construction with a coated mild steel outer casing provides a durable cylinder solution.
Safety & Performance
The Joule Invacyl 210L is designed for unvented hot-water applications with a maximum mains water pressure of 10 bar and an operating pressure of 7 bar. The specified safety temperature is 90°C, and the cylinder is tested to BS EN 50440:2015.
Its dense 50mm PU foam insulation provides effective thermal retention, with a stated heat loss of 1.8 kWh/24h. The cylinder also includes two 3kW immersion heaters operating at 230V.
Technical Specifications
| Product Model | Joule Invacyl Slimline Direct Unvented Cylinder (210L) |
| Actual Capacity | 210 L |
| Unit Weight Empty | 41 kg |
| Unit Weight Full | 243 kg |
| Cylinder Material | LDX 2101 Stainless Steel |
| Outer Casing | Coated Mild Steel |
| Thermal Insulation | Dense PU Foam |
| Foam Thickness | 50 mm |
| Number of Immersions | 2 |
| Immersion Specification | 3 kW @ 230 V |
| Maximum Mains Water Pressure | 10 bar |
| Operating Pressure (T & P) | 7 bar |
| Safety Temperature | 90°C |
| Heat Loss | 1.8 kWh/24h |
| Tested To Standard | BS EN 50440:2015 |
| Warranty Terms | 25 Years |
Ideal For
- Larger residential homes and family properties with multiple bathrooms
- Multi-occupancy or shared properties requiring a consistent hot-water supply
- Renovation projects where available space is limited but higher capacity is required
- Kitchens and bathrooms with simultaneous outlet use, including showers, taps and appliances
- Small commercial or office settings with moderate-to-high hot-water requirements
Frequently Asked Questions
What is the capacity of the Joule Invacyl 210L?
The cylinder has an actual hot-water capacity of 210 litres.
Is the Joule Invacyl 210L a direct unvented cylinder?
Yes. The Joule Invacyl 210L is a direct unvented hot-water cylinder fitted with two 3kW immersion heaters.
What material is the cylinder made from?
The cylinder is manufactured from LDX 2101 stainless steel and has a coated mild steel outer casing.
How many immersion heaters does it have?
The Joule Invacyl 210L has two immersion heaters, each specified at 3kW @ 230V.
What is the warranty?
The Joule Invacyl Slimline Direct Unvented Cylinder 210L has a stated 25-year warranty.
High-Capacity Hot Water in a Slimline Design
With 210 litres of storage, dual 3kW immersion heaters, 50mm PU foam insulation and a durable LDX 2101 stainless steel construction, the Joule Invacyl Slimline Direct Unvented Cylinder is designed for larger hot-water requirements where installation space also needs to be considered.
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