Arrived onsite to inspect error code 13 on stat. Checked unit operation and inspected heat assembly. Found gas train to be shifted enough to not allow gas to shoot through tubes. Causing the rollout switch to trip. Shut down unit, shut down gas flow, and disconnected gas line. reposition gas train to shoot through tubes and reset rollout switch. Tested unit in heat test mode unit now running properly and heating with out error. Warranty per Alex.