Teaching program comprehension is a challenging task for non-specialist computing teachers, particularly those with limited programming experience. To support this ongoing challenge, the Block Model was adapted for use with block-based programming by non-specialist computing educators. The adapted model, within FLARE, is comprised of four elements: (i) Block; (ii) Segment; (iii) Relationships, and (iv) Macro. A small-scale exploratory study was conducted as part of a teacher inquiry project. Three primary teachers were supported to apply the model to their classroom practice using a toolkit of materials. Teachers highlighted how the model supported lesson planning and dialogic teaching. However, some teachers noted issues with terminology and the need for additional scaffolding and support. Our findings have implications for teachers and resource developers interested in how computing teachers can be supported to teach program comprehension and foster classroom discussions.