Gas fired water circulation heater

摘要

The heater has feed and return unions for an external heating system, and which are connected together by piping passing through a pump and a heat-transfer unit exposed to the combustion gases. Part of this piping forms cooling piping running along the walls of a combustion chamber between the gas burner and the transfer unit. The cooling piping (32) for the combustion chamber (28) is connected at its inlet to the outlet from the transfer unit (26), and can be arranged to connect the latter to the feed union (36). Where the chamber has a front wall (41) detachable from its sidewalls, this can be cooled by a section of pipe (42) connected to the remaining portion of the piping downstream of the transfer unit. This section of pipe can be so dimensioned and connected that it acts as a bypass for the minimum amount of water circulating.