I agree with using a screen to hide the heater, but you shouldn’t place a plant directly on the heater…. hang a plant from the ceiling above the screen.

I wouldn’t do anything too intricate if I were you. If you ever need to call someone to come fix it, they might not if it’s surrounded by/ covered in stuff. And, believe me, if they’ve got to move your stuff out of the way to get to it they’ll hate you. I would just put a screen around it.

That is a strange situation. Most Plumbing and Safety Codes do not allow a water heater in an “occupied” room, even bathrooms, unless it is in a seperated room. I guess you are not in the U.S..

!] a curtain on a rod
2] screened panels
3] white trellis with ivy and flowers woven in it

The best way to hide this is to purchase a piece of lattace like what you would put in a garden. You can paint it any color your like to match your kitchen and then nail it over the opening. You may have to build a frame around the opening first in order to nail the lattace to if there is not one already there. Don’t worry about nailing it, you will not need to access it unless there is a problem with it and it can then easily be taken off. You want to be sure to stay away from fabric because this may catch fire!!

A folding screen works beautifully! My daughter uses on in her kitchen for the very same reason.
Hope this helps.
And congratulations on your new apt!

A room divider or dressing screen should do. Place a plant on top of the water heater.