Grant Vortex Pro Internal 26kW Oil Combi Boiler – Floor Standing | ErP A Rated | Up to 94.5% Efficient

The Grant Vortex Pro Internal 26kW Oil Combi Boiler is a premium all-in-one heating and hot water solution, purpose-built for off-grid properties without access to mains gas. Delivering up to 94.5% efficiency and an impressive hot water flow rate of 17 litres per minute, this floor-standing combi boiler provides powerful central heating and instant hot water from a single, highly efficient appliance  making it one of the most capable oil combi boilers available for medium to larger domestic properties.

Built around a large surface area heat exchanger for superior hot water delivery and the trusted Riello RDB burner with plug-and-play connection, the Vortex Pro Internal is engineered for reliability, ease of servicing, and long-term performance. Its biofuel compatibility and ErP A rating make it a future-ready investment for modern oil-fired heating systems.

Ideal For

• Off-grid properties requiring oil-fired central heating and instant hot water from a single unit
• Medium to larger homes needing a high-output 26kW combi boiler
• Replacement of existing internal floor-standing oil combi boilers
• Installers seeking a straightforward, serviceable combi with front access and plug-and-play burner connection
• Properties seeking biofuel-compatible, future-ready heating solutions
• Installations using Grant EZ-Fit flue systems

Why Choose the Grant Vortex Pro Internal 26kW Oil Combi?

• Up to 94.5% Efficiency – ErP A rated with outstanding condensing performance, significantly reducing fuel consumption and running costs compared to non-condensing alternatives.
• 26kW Output & 17 l/min Hot Water Flow Rate – Powerful enough for medium to larger homes, delivering strong shower and bath performance without a separate cylinder.
• Large Surface Area Heat Exchanger – Increased heat exchanger surface area maximises hot water delivery and improves overall system efficiency.
• Riello RDB Burner with Plug-and-Play Connection – Industry-leading burner technology with plug-and-socket connection to the control panel for fast, tool-free removal during servicing.
• 24-Litre Expansion Vessel Included – Supplied as standard, reducing additional parts costs and installation time on site.
• High-Efficiency Pump – Reduces electrical running costs and improves overall system performance.
• Neon Diagnostic Indicators – Clear fault indication for fast, efficient fault-finding and reduced engineer time on site.
• Heating & Hot Water Selector Switches – Simple, intuitive controls for straightforward operation by homeowners.
• Grant EZ-Fit Flue Compatible – Designed for use with Grant’s EZ-Fit flue system for simplified, flexible flue installation.
• Biofuel Compatible – Compatible with certain biofuel blends, future-proofing the installation as low-carbon fuel alternatives become more widely available.
• NOx Class 2 & 51dB Quiet Operation – Low-emission, quiet performance suitable for internal utility room and plant room installations.
• Tiered Warranty Up to 5 Years – 1-year standard; 2 years if registered within 30 days; extended to 5 years when installed by a registered G1 installer with a Grant or equivalent filter.

Technical Specifications

• Brand: Grant
• Range: Vortex Pro
• Product Type: Internal Oil Combi Boiler
• Mount Type: Floor Standing (Internal)
• Fuel Type: Oil (Biofuel compatible – subject to type and blend)
• Heat Output: 26 kW (approx. 90,000 BTU/h)
• CH Condensing Max Output: 26 kW
• DHW Output: 26 kW
• DHW Flow Rate at 35°C Rise: 17 l/min
• Efficiency: Up to 94.5%
• Energy Efficiency Rating: A (ErP)
• NOx Class: Class 2
• Noise Level: 51 dB
• Height: 860mm
• Width: 614mm
• Depth: 606mm
• Expansion Vessel: 24 litres (supplied as standard)
• Burner: Riello RDB with plug-and-play connection
• Flue Compatibility: Grant EZ-Fit flue systems
• Diagnostic: Neon diagnostic indicators
• Controls: Heating & hot water selector switches; analogue display
• Warranty: 1 year standard; 2 years if registered within 30 days; up to 5 years with G1 installer and Grant/equivalent filter

What’s Included

• 1 x Grant Vortex Pro Internal 26kW Oil Combi Boiler
• 24-litre expansion vessel
• Manufacturer’s installation and user documentation
• Note: Flue system and accessories sold separately. Oil storage tank required. Extended warranty requires G1 installer registration and compatible filter.

Installation & Compliance Notes

The Grant Vortex Pro Internal Combi must be installed by a registered OFTEC engineer in accordance with BS 5410, current Building Regulations, and the manufacturer’s installation guidelines. An oil storage tank compliant with the Control of Pollution (Oil Storage) Regulations must be in place prior to installation.

Flue installation must comply with the manufacturer’s EZ-Fit flue design guidelines and relevant Building Regulations. Condensate discharge must comply with BS EN 14336 and the manufacturer’s guidelines. For maximum warranty coverage, installation must be carried out by a Grant G1 registered installer with a Grant or equivalent system filter fitted. Always commission and test the system in accordance with OFTEC procedures prior to handover.

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