This work studies the aging of materials in a polycarbonate/chlorinated polyvinyl chloride (PC/CPVC) arrangement, used in a flat plate thermo-solar collector. Typically, PC is used as an absorbing surface and CPVC in entrance and exit heads of the flow, which in this case is water. In this study, two types of methacrylate adhesives were used to bond both plastics, denominated MP and SK. The experiment comprised a study of adhesion behavior between these polymers and the adhesives, in contact with distilled water at different temperatures and different time intervals, simulating the corresponding operating conditions of a thermo-solar collector. Results showed that the SK adhesive did not fail under these conditions, while the MP adhesive underwent evident aging and adhesive failure. In addition, the PC presented a reduction in its mechanical strength when it was subjected to higher temperatures and periods of hygrothermal exposure, probably due to physicochemical deterioration caused by hydrolysis.