We've been getting alot of rain in Phoenix, AZ. I had a service call for water in return duct. I get there and find the customer had pulled off one of the return grills. Look down and see water. So I go to the outside mechanical closet. All dry around the furnace and water heater. I pull the blower and see alot of water in the return duct. This is the kind that uses big plastic pipe. Customer has lots of water ponding in the yard. So much that he's using a sumersible pump to drian his yard. So we throw the pump down the return duct. It takes 45 minutes to get the water out of the return.

How would you fix this problem?