Hide It in a Closet or Cabinet
If you have an extra unused closet or cabinet in your bathroom, you could mount the water heater inside. If you do this, make sure that there’s at least 12 inches of free space on all sides of the water heater.
Place It in a Remote Location
If your bathroom is large enough, try moving the water heater to a more remote part of the bathroom where it would be less noticeable. Just be sure to check with a plumber to make sure that the water heater can be placed in that location.
Hung on a wall and used as a focal point
Placed in a niche or alcove. This can be a good option if you have an awkward or unused space in your bathroom.