The Grant Vortex Pro 21kW External Combi is a highly durable outdoor oil boiler designed to provide autonomous space heating and instantaneous domestic hot water for properties with restricted internal space. Housed within a resilient grey powder-coated external casing, this 181kg floor-standing unit features an integrated condensate trap and a comprehensive 24-litre expansion vessel. By combining a patented Grant stainless steel heat exchanger with a low NOx Riello RDB burner, the system delivers an impressive 90.81% space heating efficiency while adhering strictly to Class 2 NOx emission standards.

Engineered for reliable all-weather operation, the appliance incorporates an electronic boiler thermostat and an essential built-in frost stat to maintain fluid mobility during freezing conditions. The factory-fitted multi-directional flue system ensures exhaust gases are safely routed regardless of the specific external wall orientation. To assist heating engineers during routine servicing, the front control panel features clear neon diagnostic indicators and a simple plug-and-socket connection for the Riello burner, significantly reducing operational downtime.

Q: How does the unit prevent internal freezing during winter?
A: The system incorporates a dedicated built-in frost stat to automatically fire the boiler in sub-zero temperatures.

Q: What is the primary construction material of the heat exchanger?
A: The internal heat exchanger is manufactured from robust stainless steel to ensure rapid thermal recovery.

Q: Are there visual aids for troubleshooting?
A: The control interface features dedicated neon diagnostic indicators to quickly identify operational statuses.

Q: Is the condensate trap located internally?
A: It features a factory-fitted internal condensate trap which can be relocated externally if the installation requires.