We have moved into an older mobile home and the hot water heater has pvc pipe instead of copper, the landlord told us the tenants before us used it that way. I would like to know if it is safe to use it this way.

PVC is not rated for the hot side of the heater. Are you sure it is PVC and not CPVC? Is it white or cream color? Or are we talking about the CW supply? Please clarify.