I Live on the main floor of a 6 unit apartment. Somedays when I shower water is hot for the first few minutes then gradually turns cold. I then turn the hot knob full on but that doesn't help. I share my apartment with two others but they don't seem to have the same problem. Is it possible that someone in our building is playing tricks on me knowing well that it is me taking the shower as the problem only occurs when I am using the shower?

Are all of you using the same shower? Are the roomates home when this happens to you? Has it ever happened when they were not home?

Someone would have to be very dedicated to playing tricks on you to wait around listening, figure out it was you and not anyone else in the building taking a shower, figure out no one else was taking a shower, and so on. If anyone is making you run out of hot water, it's a roommate. Pretend to be in the shower and sneak out to the kitchen. But I think you are dreaming.

Chances are you take your shower too soon after someone else, or use too much pressure, or take a longer shower, or take showers at a time of day when the whole building is using up the water.

Find out what kind of hot water heater your apartment has, or how the whole building gets it.