The heating element in the 110 volt and 220 volt pots have a different part # so using one leg of the 220 in order to use 110 volts will not work. It would be sort of like trying to use one leg of your 220 to bake biscuits. Plus the 220 volt pot uses a different thermostat. Plus if you get the 220 volt pot the cord does NOT come with a plug.
Lee needs to get with the times and re-label the electrical specifications for those pots. The US hasn't used the 110/220 rating since the 50'/60's eventually going to 115/230 and now 120/240. It must be because of the European use of 220 in the wall receptacles as to why Lee still uses that rating.
