Goodman unit installed approx. 1 year ago. For past 2 days when AC is on, have noticed a lot of water on shelf of unit that has also drained into pan on floor. Air is cool so appears to be working but don't know where water is coming from. Had a leak during past winter onto same shelf area and the flue needed silicone application. Also found large area of rust in both lower cabinets recently. Again, don't know why so many issues with newly installed system.