I have a multi output process that I modeled in openLCA (1.7.0 on Mac). One of the outputs is heat (heat, district or industrial, other than natural gas). When I want to calculate the allocation factors for my other output processes I need to mark this as an avoided product. Otherwise the other allocation factors are calculated to zero. Why is this? I have not assigned any price to the heat (but to my other three products which I am interested in). Do I have to give heat a price as well or is there a bug?