Installed hose clamps on the 3 rubber tubes - but still leaks into the bottom of the furnace. Any ideas on how to get it to stop leaking - the furnace is about 4 months old.

4 months old, isn't it still under warranty?

Check to make sure the clamps on the flue exhaust pipe exiting the inducer motor housing are tight.

Thanks, Yes it is under warranty - but I hate not knowing (a little geekie that way).
I took the trap off and sealed the 3 inlet ports and blew air into the larger port on the trap to see if there were any leaks - there were no air leaks.
The Trap is attached with a galvanized 'L' bracket to the side of the furnace. I noticed that the PVC drain tube was pitched up due to the 'L' bracket being installed a little too low for the exit hole, making the trap's drain a little to high allowing the water to build up before it flows out of the trap.
So... I re-drilled the 'L' bracket to raise the trap and make it level. Then I found that the PVC drain tube was not glued so I used a silicone adhesive and glue it in.
99% of the leak is gone now but there is a trace still dripping from the trap into the base of the furnace - all the hoses are tightly attached.

The pvc should be glued into the trap with pvc glue and cleaner. Is that the joint that is still leaking? I haven't sold a rheem for about five years, but they used to only have two inlet ports and one outlet. Do the new ones have three inlet ports? Either way, I would get the installer back to fix this. If you damage anything while working on it yourself, warranty may be void. I know, sad, but true. Make the installer stand behind his work, and his equiptment. That's part of why we charge what we charge:)