Joule Invacyl Slimline Direct 90–210L Unvented Hot Water Cylinder

Joule Invacyl Slimline Direct 90–210L Unvented Hot Water Cylinder

The Joule Invacyl Slimline Direct Unvented Cylinder (available in 90L, 120L, 150L, 180L, and 210L models) is expertly designed for compact spaces, offering all the pressure performance and efficiency of a premium unvented hot water system—without compromising on storage or output. Engineered with quality Duplex stainless steel, these cylinders are an ideal choice for homes and flats in need of a slimmer cylinder profile to fit restrictive airing cupboards or tight plant rooms.

Key Features:

• Slimline diameter (approx. 475mm across most sizes) – designed for flexible installation in narrow cupboards
• Direct electric heating – factory-fitted with high-quality immersion elements for all-electric operation
• Mains pressure unvented design – delivers consistent high-flow hot water to multiple taps or showers, even at peak times
• Premium Duplex stainless steel construction for long-term durability and corrosion resistance, ideal for hard water areas
• Caleffi safety valve group and compression fittings supplied as standard for safe, reliable installation
• Gloss white outer case with dense, eco-friendly polyurethane foam insulation for outstanding heat retention
• Complies with all UK Building Regulations and WRAS approved
• Generous 25-year warranty on the cylinder (terms apply) plus 2 years on electrical and safety components

Technical Specifications:

• Available capacities: 90L, 120L, 150L, 180L, 210L
• Slimline diameter: approx. 475mm (check size chart for exact models)
• Height example: 90L – 936mm; 120L – 1205mm; 150L – 1324mm; 180L – 1469mm; 210L – 1712mm
• Electrical: Twin factory-fitted 3kW Incoloy immersion heaters (or as specified per model)
• Maximum working pressure: 3.5 bar with supplied inlet controls
• Safety group: Caleffi T&P valve, expansion vessel, and tundish included
• Insulation: CFC/HCFC-free dense PU foam (ozone-friendly, high-efficiency)
• Connections: Screwed with compression fittings – easy to adapt to UK pipework

Other Details:

• Carefully engineered for energy efficiency, safety, and ease of installation
• Perfect for flats, conversions, and homes with restricted cylinder cupboards
• Supplied with full installation instructions and all required fittings
• Compatible with standard timers, thermostats, and mains pressure systems

Why Choose the Joule Invacyl Slimline Direct Cylinder?

The Joule Invacyl Slimline Direct range offers an industry-leading solution for hot water in space-constrained UK properties. Trusted stainless steel construction, powerful electric-only performance, and an ultra-slim profile deliver peace of mind, energy savings, and the flexibility to fit almost anywhere—while the long warranty ensures years of mains pressure hot water comfort.