Abstract: Apparatus for expelling air from a liquid storage tank, such as a hot water storage tank includes a bleed line coupled between a water circulating pump discharge conduit and a hot water discharge line emanating from tank 10. The bleed line is connected to the hot water discharge line at a location which is elevated with respect to a location where the bleed line is connected to the pump discharge conduit. The pump is operable to draw hot water from the top part of the tank and discharge it into a cold water fill line extending into the tank to enhance water circulation in the tank. Air and other gas released when water is heated in the top part of the tank are drawn from the top part of the tank and expelled via the bleed line, to prevent accumulation of air and other gas in the tank. In accordance with another aspect of the invention, an elongated tubular member is inserted into the cold water fill line.

Abstract: A combination water heating and space heating apparatus includes a water heating unit and a space heating unit releasably coupled with the water heating unit. The water heating unit has a water storage tank and a helically wound tubular heat exchanger inside the tank for exhausting products of combustion from a combustion chamber located in a top part of the tank and for transferring heat from the products of combustion to the surrounding water. The space heating unit is an air handler with an hydronic heat exchanger coil and a blower for blowing air over the coil. Hot water is supplied from the tank to the coil and is returned to the tank by means of a water circulation pump located in the space heating unit. Air blown over the coil is heated by the hot water flowing over the coil.

Abstract: An improved combustion chamber for a condensing furnace comprising an elongated cast body having a mixing chamber for receiving fuel and air and an expansion chamber communicating with said mixing chamber, a fuel inlet in said body communicating with said mixing chamber, an air inlet in said body communicating with said mixing chamber and means for igniting the air fuel mixture in said mixing chamber, the fuel inlet and the igniting means being opposed to one another to enhance the ignition of the fuel and air in the mixing chamber. An important feature of the invention is the critical ratio of the transverse cross sectional area of the expansion chamber to the transverse cross sectional area of the mixing chamber for maintaining continuity of operation. Such ratio should be about 2/1 to 2.4/1. In a preferred form of the invention, the igniting means is a spark plug and the spark plug opening into the mixing chamber is co-axial with the fuel inlet.