H21a. Which fuel is used most for house heating?
[] Gas: from underground pipes serving the neighborhood
[] Gas: bottled, tank, or LP
[] Electricity
[] Fuel oil, kerosene, etc.
[] Coal or coke
[] Wood
[] Other fuel
[] No fuel used
[Gas from underground pipes is piped in from a central system such as one operated by a public utility company or a municipal government. Bottled, tank or LP gas is stored in tanks which are refilled or exchanged when empty. Other fuel includes any fuel not separately listed, for example, purchased steam, fuel briquettes, waste material, etc.]