Flexiheat UK offers a comprehensive portfolio of boilers, water heaters, warm air heaters, buffer tanks, air curtains and complementary heating solutions,ranging from gas, oil or electric boilers to fan heaters and to suit residential, commercial and industrial installations. Whether you’re specifying condensing gas boilers to suspended gas heaters for large warehouses, every product is engineered for straightforward installation by professional heating installers.

Quality Assurance

The equipment we supply is manufactured under robust quality-management systems, such as ISO 9001 and ISO 14001 certification, ensuring consistent performance and environmental stewardship, backed UKCA and CE marking for safety and regulatory compliance, and emissions verification, to guarantee long-term reliability even in demanding applications.

Customer Service & Design Support

From your first enquiry, our UK-based specialists deliver free system selection /design advise, and bespoke quotations- helping you select the ideal combination of boiler outputs, heater capacities and controls for every project. Need help interpreting performance data or co-ordinating you’re heating or domestic hot water installations? Simply call 01202 822221 or email sales@flexiheatuk.com for prompt, actionable advice from our technical team.

After-Sales Support

Ongoing support extends well beyond delivery: installers gain access to detailed installation manuals, troubleshooting flowcharts and firmware updates for smart controllers. Our priority spare-parts service and warranty options ensure you can meet tight project deadlines and confidently guarantee your work to third-party property owners. Should additional on-site assistance be required, we’ll connect you with certified service technicians to keep every system running at peak efficiency.

170 Litre direct unvented cylinder in highly corrosion resistant duplex stainless steel with 2 x 3kW immersion heaters for mains pressure hot water.Flexiheat UK

170 Litre Direct Unvented Cylinder

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Crafted from high-grade duplex stainless steel and powered by twin 3 kW immersion heaters, the 170 L Direct Unvented Cylinder delivers mains-pressure hot water without the need for gas or oil boilers. Its patented internal venturi expansion system maintains a self-sustaining air pocket—eliminating external expansion vessels and reducing both installation time and lifetime maintenance. Manufactured under stringent UK quality controls and backed by a 25-year corrosion warranty, this cylinder ensures reliable performance in demanding residential and commercial settings while simplifying the installer’s workflow with minimal moving parts and clear, contractor-friendly specifications.

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200 Litre direct unvented cylinder in highly corrosion resistant duplex stainless steel with 2 x 3kW immersion heaters as standard or the option of 3 x3kW immersion heaters for mains pressure hot water from Flexiheat UKFlexiheat UK

200 Litre Direct Unvented Cylinder Water Heater

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200 Litre direct unvented cylinder – Electric water heater Looking for a 200 litre direct unvented cylinder or 210 litre direct unvented cylinder in duplex stainless steel ? then we have you covered as we supply a 215 litre direct unvented cylinder which covers these direct models hot water capacity. Manufactured in the UK, with […]

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300 litre direct unvented cylinder in stainless steel, using 100% energy efficient immersion heaters to heat these hot water cylinders to provide water heating for bathroom and showers with a 25 year warranty for domestic use from Flexiheat UKFlexiheat UK

300 Litre Direct Unvented Cylinder Water Heater

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300 Litre direct unvented cylinder Our 300 litre direct unvented cylinder is engineered in corrosion-resistant duplex stainless steel and is a competitively priced cylinder. We designed it to achieve high flow rates and a long product life using proven technology and a quality manufacturing process for this unvented hot water cylinder for mains pressure hot […]

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210 Litre indirect unvented cylinder in stainless steel for the delivery of mains pressure hot water heating with no expansion vessel required and reduce heat loss insulation for low water heating losses and with WRAS independent approvals from Flexiheat UK.Flexiheat UK

210 Litre Indirect Unvented Cylinder

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210 Litre indirect unvented cylinder Our 210 litre indirect unvented cylinder is the best and most competitively priced cylinder on the UK market, manufactured in stainless steel with proven technology and quality manufacturing for maximum life with the capacity to supply mains pressure hot water for your bathroom, shower, wet rooms, and kitchen tap hot […]

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400 Litre indirect unvented cylinder or 400 litre unvented hot water cylinder in stainless steel for the delivery of mains pressure hot water heating with reduce heat loss manufactured insulation for low water heating losses from Flexiheat UKFlexiheat UK

400 Litre indirect unvented cylinder

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400 Litre indirect unvented cylinder   Our 400 litre indirect unvented cylinder, or calorifier, is manufactured in stainless steel with proven technology and quality manufacturing processes and has the capacity to supply your mains pressure hot water demands for your bathrooms, showers, wet rooms, and hot water taps. Conventional boiler fed This indirect unvented cylinder […]

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150 Litre indirect unvented cylinder in stainless steel for the delivery of mains pressure hot water heating with no expansion vessel required and reduce heat loss manufactured insulation for low water heating losses and with WRAS independent approvals from Flexiheat UK

150 Litre Indirect Unvented Cylinder

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150 Litre indirect unvented cylinder Our 150 litre indirect unvented cylinder is the best and competitively priced cylinder on the UK market, manufactured in duplex stainless steel with proven technology and quality manufacturing with the capacity to supply mains pressure hot water for your bathroom, shower, wet rooms, and kitchen tap hot water demands in […]

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Industrial gas water heaters in natural gas or LPG propane from Flexiheat UKFlexiheat UK

Industrial gas water heaters

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Industrial gas water heaters Our industrial gas water heaters are condensing water heaters for maximum energy efficiency and lower hot water heating bills. This industrial gas fired water heater can be used in an industrial instant hot water heater configuration but also can be linked up to a hot water storage tank for water heating […]

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500 Litre indirect unvented cylinder in stainless steel for the delivery of mains pressure hot water heating with no expansion vessel required and reduce heat loss insulation for low water heating losses from Flexiheat UKFlexiheat UK

500 Litre indirect unvented cylinder

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500 Litre indirect unvented cylinder Our 500 litre indirect unvented cylinder or calorifier options are some of the best and competitively priced cylinders on the UK market, manufactured in stainless steel (or the option of glass lined) with proven technology and quality manufacturing with the capacity to supply mains pressure hot water for your bathroom, […]

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120 Litre direct unvented cylinder in highly corrosion resistant duplex stainless steel with 2 x 3kW immersion heaters for mains pressure hot waterFlexiheat UK

120 Litre Direct Unvented Cylinder

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120 Litre direct unvented cylinder   Our 120 litre direct unvented cylinder is engineered in corrosion-resistant duplex stainless steel and is a competitively priced cylinder. We designed it to achieve high flow rates and a long product life using proven technology and a quality manufacturing process for this unvented hot water cylinder for mains pressure […]

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150 Litre direct unvented cylinder in highly corrosion resistant duplex stainless steel with 2 x 3kW immersion heaters for mains pressure hot waterFlexiheat UK

150 Litre Direct Unvented Cylinder

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150 Litre direct unvented cylinder Our 150 Litre direct unvented cylinder is a competitively priced cylinder manufactured for mains pressure hot water and engineered in corrosion-resistant duplex stainless steel for high flow rates and longevity of performance via quality manufacturing processes. So confident are we in the quality of our 150 litre unvented direct cylinder […]

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