Abstract: The invention concerns a mixing device for mixing gas and combustion air for a gas burner. According to the invention, a mixture of gas and combustion air prepared in said mixing device (10) is sent to the gas burner through a blower, the mixing device (10) comprising a housing (13) and a venturi (14). The invention is characterized in that the venturi (14) is integrated in the housing (13) such that the housing (13) and the venturi (14) form a single block.

Abstract: A gas valve body with a first flow chamber and, a second flow chamber including and a main valve positioned in line and between the first flow chamber and the second flow chamber. The main valve can be opened by creating a pressure differential across the main valve. An electrostatically controlled pilot valve is provided for controlling the pressure differential across the main valve for “on-ff” operation. The electrostatically controlled pilot valve may also be operated to “modulate” the pressure differential across the main valve along a range of pressure differential values.