Performed furnace clean and tune; started with inspecting the Evap coil did find some indicators of a leak, inspected the exhaust and intake PVC ensuring all connections were secured, removed and cleaned the burners along with the flame sensor, cycled the system on and checked gas pressures, as well as performed a combustion test verifying no CO in the airstream. Because I found Indicators of a leak on the AC system I highly recommend having maintenance done this spring. This system is currently operating normal and heating at 47 degrees at this time job complete