Complete 2 system furnace repair and preventative maintenance check. Checked filters, only upstairs needed changing. Thermostat upstairs was not engaging in heating mode, removed thermostat from the wall and tested all wires. Heating worked when I wired W to R. I reinstalled thermostat to the wall and it is now fully operational. Tested static pressures and all electrical components for upstairs. All readings were within range. The downstairs unit had NO tape on supply plenum. Fixed leakage with silver tape. Quieted a rattling sound that came from flu pipe by adding an extra screw to secure tighter. Tested Static pressure and all electrical components, all readings were within range.