Some general notes on U.K. domestic practice. A reminder: All units are 2-wire (plus ground) 240V.
Unlike their U.S. counterparts, the majority of British washers incorporate a heating element, almost always 3kW. They also, on average, tend to be smaller capacities than in America. (That pretty much sums up everything in Britain!)
Some machines have only a cold inlet, while others take both cold & hot supplies. Even on a cool wash setting the blend of water is usually such that the internal heater is needed to achieve the required temperature.
Top loaders are available, but front-loading washers are much more common these days and generally cheaper too. Dedicated laundry/utility rooms are not so common here, so the majority of machines end up in the kitchen area under a worktop (perhaps another reason for the popularity of the front loader?).
Power is most often via a regular 13A plug & socket, the latter generally being part of the general-purpose 30A ring. A dedicated circuit is found occasionally, but is very rare.
Despite the notoriously fickle and unpredictable weather in this country, many people prefer outdoor "natural" drying, so dryers aren't so popular as in the States. (And in some small British homes there just isn't enough space for one.)
Like washers, dryers here tend to be of smaller capacity, and most have a 3kW heater so that they can run on a normal 13A plug/socket. Again, this is most often one on the 30A ring. A few (very few) units are higher powered -- about 4kW -- and these need their own dedicated 20A circuit.
Gas dryers are available, but very rare.
Just about the same comments as for clothes washers apply here: Built-in 3kW heating element, cold or hot/cold fill depending on model, and usually powered by a normal 13A outlet.
There you have it. I have some views on the unsuitability of our present electrical arrangements for these appliances, but I'll wait a while before getting on my soap-box.
[This message has been edited by pauluk (edited 12-16-2001).]