Warranty Grayson. Completed diagnostic. Found screws for furnace door had come loose causing it to deactivate door switch turning off the furnace. Replaced screw and made sure it was tight to avoid happening again. Evap coil and blower are clean. All electrical components are working. System missing secondary water safety switch. Home would benefit from having CO detector installed as well as Uv light system installed in furnace to clean air and kill any bacteria or viruses that could be harmful to residents.