Compact and stylish boiler with quiet operation and no carbon monoxide output. Requires no flue and includes expansion vessel and pump with touchscreen operation and display. Uses Serpentine heating element technology. Compatible with solar panels. Max. Central Heating Output: 21kW Serpentine Heating Element Compatible with Vented or Unvented Indirect Cylinder Compatible with Solar Panels 2 Year Manufacturers Guarantee (Registration Required, T&Cs Apply) 71,600BTU LED Digital Display Incorporates Expansion Vessel & Pump Touchscreen Operation & Display Max. Central Heating Output: 21kW Serpentine Heating Element Compatible with Vented or Unvented Indirect Cylinder Compatible with Solar Panels 2 Year Manufacturers Guarantee (Registration Required, T&Cs Apply) 71,600BTU LED Digital Display Incorporates Expansion Vessel & Pump Touchscreen Operation & Display