Water leaking inside RV from furnace.

The furnace is underneath the fridge. We have a residential frig and I don't see any vent on the roof. When I had our TT, we had a absorption fridge that did have a vent. Everything I have read is the vent tube should have a 45 degree angle up so water doesn't get inside the furnace. My tube angels down. This has happened twice now and both times I had a heavy sheeting rain against the side of the motorhome that the furnace is on. The first time I couldn't figure out where it was coming from. This time, I pulled out the bottom drawer that is near the floor next to the fridge. I could see water dripping from the bottom of the furnace near a screw that holds the bottom sheet metal of the furnace. There was no water running on top of the furnace under the fridge. As you can see in the picture above, the vent tube angles down so any water blowing in the vent hole is going to drain into the furnace.