The S-FX range comprises four floor standing models of a highly efficient, stainless steel, ultra low NOx emission gas condensing ‘vertical tube bundle’ boiler offering an output range from 15kW to 320kW at 50°C/30°C (F/R) with 70kW, 125kW, 220kW and 320kW (Sold out! New updated version available here) individual boiler nominal outputs. Each boiler offers NOx emissions of less than 24 mg/kWh (Class 6) in compliance with the maximum 2 credits available under BREEAM’s New Construction 2018 1.0 Technical Manual SD5078 guidelines.
With Seasonal Efficiency across the range in excess of 96.75% to Part L calculations the entire range is also extremely fuel efficient due to the combination of ‘near perfect’ flat-plate pre-mix burner combustion combined with the benefits of dual gas and water side turbulence around the uniquely shaped heat exchanger tubes.
The S-FX boiler offers a large water content design with no minimum flow rate removing the need for an additional primary side circulation pump. The S-FX 320kW boiler has generous water content of 550 litres. Additionally, the boiler can also be configured to store water at a predetermined temperature set-point to act as an ‘on demand’ buffer of hot water so that, for example, a cascade of three S-FX 320 boilers could provide space heating as well as acting as a 1650 litre vessel. The boiler is flued from the bottom and has three positional options for rear hydraulic connections.