Gas is good but electricity is too expensive!
If in the US you got to use the gas (either with internal washer heater than with the central gas heater sistem), you would get in my opinion the best sistem to heat laundry water!
Here in Italy we have 220V and wahsers use electricity to go on, but here electricity is not produced with nuclear sources, and although we have the Alpes and almost the 90% of electricity we produce come from idro-electrical centrals, and the remaining 10% come from wind or geo-thermic sources, the production is not enough: that's why we have to import the electricity we need more by other confinant country, as France or Swiss, and this make electricity for italian bills very very expensive.
We would use the gas (which costs less than electricity power)but there is not any washer sold in Italy which allow you to do it. I think it's the same even for the other countries in the Europe. You might hold the only washer hose provided for the cold water on the hot water (coming from the central gas burner), but I don't know anyone who did it, even because you would do the rinse cycle with hot water too.
Of fourse for the US people would be a very good step ahead to reach 220V and add some oultlets more in their houses, because I heard you speaking of very few oulets in the apartement, thinking that here we have at least 4 outlet and 1 ceiling light per room, if you consider livignroom or bedroom, becasue in kitchen they can raise up to 2 or 3 light point and 7 or 8 outlet.
Ah, I'm forgetting the maximum of the power you cas use that's 3300W if your electric contract is of 3Kw, 5000W if your electric contract is of 4,5 Kw and 6000W if your contract is of 6Kw.
If you have 3Kw contract your circuit need only two fuses 16A for electric oven or if you have some electric stove, 10A for anithig else. Some years ago, any appliances with an electric internal heater must have been held on a 16A outlet, now only the electric ovens, because the heater of the washers and the dishwashers can go on even on a 10A circuit. You might require a 25A or more if have more than a 3Kw contract (4,5 or 6), to allow you to use more than a heater contemporanealy, without any risk of blackout.
That's all for a graet topic which discuss on.
Good Bye
Diomede