- Is your house wired for the load? (e.g. you need bigger wires to handle the higher amperage. Walls might need to be taken down in order to rewire the appliances)
Those are the two biggest issues. Depending on your house layout, you might basically need to gut your entire house just to rewire a single appliance. I'm obviously throwing out a catastrophic example here, but it can happen. This sort of thing is best done if you're doing major renovations anyway.