In a commercial lease, the tenant moved at the end of the lease and took the water heater. Is he responsible for replacing it? I believe there was a water heater there when he moved in but that he replaced it with a larger water heater.
Usually a commercial lease will address the question of "fixtures". In the absence of any mention in the lease (and no other agreement regarding the topic), an item such as a water heater would generally become part of the property, and should not have been removed at the end of the tenancy.