Gas boiler OSA S

for heating onlywall-mountedresidential

Wall hung, extra thin, low NOx, room sealed, condensing gas boiler with electronic ignition and continuous modulation, with DHW production. Front panel in different colours. Registered design Thanks to U-Fly, the integral disappearing control console, connected to the room and outdoor temperature sensors, reaches, in heating mode, the seasonal efficiency class A+ Low NOx class 6 Heat exchanger / Condenser in aluminium /silicon / magnesium Total premix burner, with constant combustion ratio, completely electronic (both, gas valve and modulating fan) Ignition and electronic flame control through single electrode Modulation ratio 1:8 Automatic feed-back of the combustion through the electrode (that monitors constantly the quality of the combustion) DHW heat exchanger in antiscaling stainless steel, with 12 plates (x 24 kW) and 14 plates (x 35 kW), with “thermal length” optimized for the condensation Adjustment of output according to heating request HWS “Hot Water Speed” electronic function: commutation from heating to DHW mode without stopping the pump Management of 2 zones: high / low temperature, with differentiated priority Clever hydraulic filling of the C.H. system (able to indicate possible leakages) Electronic antifreeze function from 5°C Multigas burner (Natural gas or LPG) with silplified commutation Up-gradable through type USB interface High efficiency pump, complying with the Erp Directive 2015, modulating according to the output request, managed by the on board electronics Connection for diagnostics and programming through computer or portable Programmer Two expansion vessels (10 liters total)