Abstract: A heat exchanger for a heating device, especially a fuel value heating device, made up of at least two vertically aligned members, and, in each case, one cover at the end face, which form a combustion chamber, and laterally border at least one heating gas flue, that leads from the combustion chamber in the upper region downwards to an exhaust collector in the lower region, having heat exchanger surfaces which, on the heating gas side, are provided with elements that increase the size of surfaces, especially in the form of ribs, optionally having at least one middle member between the two bordering outer members, and having a plurality of channels guiding the heating medium flowing through in parallel and/or in series in the members and/or the covers. The present system provides a compact heat exchanger for a heating device, and which is light and is especially suitable for the fuel value operation.