Hi,
In a nutshell, I'd would say it's not worth trying to transport it back to the States.
The U.K. dishwasher is designed for a 240-volt supply whereas your dishwasher outlet in the U.S. will be 120 volts. Transformers can convert from one to the other, but unfortunately there's more to it than that. Most British dishwashers have an integral heating element of about 3 kilowatts, which in itself would necessitate a fairly large and expensive transformer. You wouldn't be able to just plug that transformer into your U.S. dishwasher outlet either, as the latter will be rated for 15 or 20 amps, which works out as 2.4kW maximum.
A lot of people don't realize that the majority of American homes do actually have 240V supplies available in them, so you could have a special 240V outlet installed for the dishwasher to get around the need for a transformer, but then you still have the frequency issue.
It's not just the voltage which is different but also the frequency (number of electrical cycles per second) which differ: 50Hz in Britain, 60Hz in America. Transformers can change voltage, but not frequency. Some motors run much less efficiently on the wrong frequency.
Aside from the electrical issues, you will then have to fabricate adapter hoses or couplers, since the 3/4-inch BSP inlets on a U.K. machine aren't interchangeable with American fittings.
So given the cost of shipping the unit over plus conversion issues and the fact that it will never run at full efficiency against the cost of buying a new machine Stateside, I would strongly suggest you leave it here.
