Tech was out due to a burning smell. Checked furnace and seen multiple issues with system. Flue pipe is is covered with tape in two different sections. This is causing tape to make a burning smell. Also flue pipe is incorrect let small amounts of carbon monoxide into the small confined area . Vent is closed making the system over heat and work harder. Gas line going to gas valve is incorrect and not up to code. Blower wheel is dirty and needing to be cleaned. Condensate pump is impacted with sediment and sludge causing pump to not properly pump water. There is no emergency drain pan under furnace to collect water if system freezes up or drain line clogged. No wet switch to detect water. Furnace filter rack is needing to be seal as well as any other areas that is able to pull garage air or any other odors / fumes. Condensers are needing condenser pads to keep vibrations or holes from coming into home. Tech has spoke with customer about these issues and is awear of all repairs that are