Returned to replace warranty blower motor. Installed new blower and cycled unit. Found system having intermittent issues with blower. Removed jumper between high cool and heat. Placed high speed tap on hi cool. Placed medium high on heat. Cycled unit. Running with 20 degree temp drop for remaining period while tech there. In duct smoke detector was tripped. Did not shit furnace power off. Advised customer system needs certification. We do not have a certified tech. Advise custom air may have needed Tech.