The Grant Vortex Pro 21kW is an internally sited, floor-standing oil-fired combination boiler engineered to supply high-performance space heating and mains-pressure domestic hot water from a single unit. Utilising Grant's patented large surface area heat exchangers with low water content, this robust appliance vastly increases thermal transfer rates to deliver incredible space heating efficiencies of up to 90.81%. The integration of an advanced Riello RDB Low NOx burner ensures the boiler adheres to the latest strict emissions targets, operating with Class 2 NOx levels while maintaining a reliable, high-yield XL load profile for demanding residential setups.

Housed within a sleek white casing measuring 860mm x 614mm x 614mm, this 160kg unit is specifically designed for utility room installations where exceptionally quiet operation is necessary. The boiler comes fully equipped with a heavy-duty 24-litre expansion vessel, a high-efficiency circulating pump, and intuitive front-mounted neon diagnostic indicators that provide straightforward fault finding and user operation. Furthermore, the appliance is fully compatible with Grant EZ-Fit flue systems and operates safely on biofuel blends depending on the specific percentage, making it an adaptable, future-proof solution for off-grid properties requiring instantaneous hot water.

Q: What size expansion vessel is fitted internally?
A: The boiler is supplied complete with a substantial 24-litre expansion vessel.

Q: Which type of burner is utilised in this oil combi boiler?
A: It utilises a high-efficiency Riello RDB burner equipped with a straightforward plug and socket connection.

Q: What are the physical dimensions of the floor-standing casing?
A: The external casing measures 860mm in height, 614mm in width and 614mm in depth.

Q: Can this boiler operate using biofuel?
A: It is biofuel compatible, strictly dependent on the specific type of biofuel and the percentage of the blend.