In the 2013 federal election, Weiler won the direct mandate for the CDU in the constituency Gera – Jena – Saale-Holzland-Kreis. He is a full member of the Committee for Labour and Social Affairs, where he serves as his parliamentary group's rapporteur on unemployment insurance and public employment agencies, including the German Federal Employment Agency (BA). In addition, he has been serving as substitute member of the Committee on Economic Affairs and Energy, substitute member of the Committee on Human Rights and Humanitarian Affairs and substitute member of the Parliamentary Advisory Board on Sustainability.