At the beginning when Lucy says "c'mon Ricky time to get up" notice that Ricky is lying in her bed! his legs are sticking out out of Lucy's bed.
When Fred comes over to fix the pipes Lucy says she told Ethel about it two years ago, but the Ricardos have only been in that particular apartment for less than a year.
In the opening scene, the Ricardo apartment is a mess and Ricky and Lucy stumble half-asleep to the breakfast table. In most episodes where there is a breakfast scene, Lucy and Ricky are dressed. If they are still in pajamas or bathrobe, they are much more presentable. Additionally, the Ricardo apartment is never as messy as it is in this episode. Lastly, Ricky is in the wrong bed. Lucy always sleeps in the bed on the left.