The Joule Invacyl Slimline Direct Unvented Cylinder 120L is a space-saving stainless steel hot water cylinder designed for unvented mains-pressure systems. With its slimline design and 120-litre capacity, it provides reliable hot water storage while helping maximise available floor and plant-room space. It is well suited to small and medium-sized homes, apartments, renovation projects and smaller commercial installations.
Manufactured using LDX 2101 stainless steel and protected by a coated mild steel outer casing, the Invacyl Slimline combines durable construction with 50mm dense PU foam insulation. With a specified heat loss of just 1.37 kWh/24h, two 3kW immersion heaters and support for mains water pressure up to 10 bar, it is designed to provide dependable hot water performance across multiple outlets.
Cylinder Type
Direct Unvented
Key Features
120-Litre Hot Water Capacity
The 120-litre capacity provides hot water storage suited to small and medium-sized households, apartments and other properties with moderate hot water requirements.
Slimline Space-Saving Design
The slimline format is designed to make efficient use of available installation space, making the cylinder suitable for renovations, retrofits and installations where floor or plant-room space is limited.
LDX 2101 Stainless Steel Construction
The cylinder is manufactured from LDX 2101 stainless steel, providing the specified corrosion-resistant construction for long-term hot water storage applications.
50mm Dense PU Foam Insulation
Dense PU foam insulation with a specified thickness of 50mm helps retain stored hot water. The cylinder has a stated heat loss of 1.37 kWh/24h.
Two 3kW Immersion Heaters
Two immersion heaters rated at 3kW @ 230V provide direct electric heating for effective hot water recovery and convenient system operation.
High-Pressure Mains Water Operation
The cylinder supports maximum mains water pressure of up to 10 bar, with a stated operating pressure of 7 bar, making it suitable for mains-pressure hot water delivery to multiple outlets.
Space-Saving Hot Water Storage
The Joule Invacyl Slimline 120L combines a compact slimline design with stainless steel construction and mains-pressure hot water storage. Its format makes it suitable for properties where available installation space needs to be used efficiently without moving away from an unvented hot water cylinder system.
Residential Hot Water
120L storage for small to medium residential properties with moderate hot water demand.
Space-Conscious Installations
Slimline construction helps make efficient use of available floor and plant-room space.
Mains-Pressure Hot Water
Designed for unvented mains-pressure hot water systems serving multiple outlets.
Direct Electric Heating
Two 3kW immersion heaters provide direct electric heating capability.
Safety & Performance
The Joule Invacyl Slimline 120L has a specified maximum mains water pressure of 10 bar, an operating pressure of 7 bar and a safety temperature of 90°C. The cylinder is stated to have been tested to BS EN 50440:2015.
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Maximum mains water pressure: 10 bar
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Operating pressure: 7 bar
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Safety temperature: 90°C
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Tested to: BS EN 50440:2015
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Warranty: 25 years
Technical Specifications
| Product Model |
Joule Invacyl Slimline Direct Unvented Cylinder (120 L) |
| Actual Capacity |
120 L |
| Unit Weight – Empty |
26 kg |
| Unit Weight – Full |
140 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 |
1.37 kWh/24h |
| Tested To Standard |
BS EN 50440:2015 |
| Warranty |
25 years |
Ideal For
The Joule Invacyl Slimline Direct 120L is suited to properties requiring compact, mains-pressure hot water storage with direct electric heating.
- Small to medium residential homes
- Apartments and multi-occupancy properties
- Renovation and retrofit projects
- Bathrooms and kitchens requiring mains-pressure hot water
- Small offices with moderate hot water demand
- Installations where space-efficient hot water storage is required
Frequently Asked Questions
What is the Joule Invacyl Slimline 120L?
The Joule Invacyl Slimline 120L is a direct unvented stainless steel hot water cylinder designed for mains-pressure hot water systems. It has a 120-litre actual capacity and a slimline design.
How many immersion heaters does the cylinder have?
The cylinder has two immersion heaters, each rated at 3kW @ 230V.
What is the heat loss of the Joule Invacyl 120L?
The specified heat loss is 1.37 kWh per 24 hours. The cylinder uses 50mm dense PU foam insulation to help retain stored hot water.
What pressure can the Joule Invacyl 120L operate at?
The maximum mains water pressure is specified as 10 bar, with an operating pressure of 7 bar.
What material is the cylinder made from?
The cylinder is manufactured from LDX 2101 stainless steel and features a coated mild steel outer casing.
What is the warranty?
The supplied product information specifies a 25-year warranty.
Joule Invacyl Slimline Direct 120L Unvented Cylinder
A space-efficient stainless steel unvented cylinder for mains-pressure hot water systems, combining 120L storage, 50mm PU foam insulation, two 3kW immersion heaters and a 25-year warranty for residential and smaller commercial applications.
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