Solar pool heating systems vary based on the pool design and size. Does this mean that every possible combination needs to be certified?

Because of the wide variety of pool and spa sizes and configurations, listings for solar water heating systems to ICC 902/PHTA 902/SRCC 400 allow for size flexibility. This means that the listing addresses a general configuration of collectors, type (direct or indirect), pool/spa tie-in, and components. The number, size, and layout of the collectors may vary to the extent permitted by the system manufacturer’s installation instruction. But, all systems covered in a listing must share the same component type, layout, pool tie-in and collector models. Where variations to the design are permitted, the listing will specifically note them, so that code officials can easily confirm whether the system they are inspecting matches the one evaluated by ICC-SRCC.