More than 24,000 Pennsylvania households are entering the winter season without heat-related utility service or are using unsafe heating sources, down 4.8 percent from last year but still higher than in previous years.

Sixty-four percent of the state's households without central heat are customers of Philadelphia Gas Works or Peco Energy Co., according to the Public Utility Commission's annual Cold Weather Survey.

PGW reported 9,252 customers without central heat, down 7.6 percent from the 2014 level. Peco, which serves electric customers in Philadelphia and surrounding counties and gas customers outside Philadelphia, reported 6,299 households without heat, a 6 percent increase.

Peco said the number of customers using potentially unsafe heating sources more than tripled, from 113 households to 386, drawing a rebuke from the Pennsylvania Utility Law Project.

"This is a clear indication that additional support is needed to address the gap in universal utility services to the state's most vulnerable individuals," said Patrick Cicero, director of the law project.

Though the statewide number was down from 2014, it was still 22 percent higher than the average of the previous four years.

The annual PUC survey highlights some dramatic regional differences in customers without heat. PPL Electric Utilities, the Allentown utility that serves 1.4 million customers in 29 counties, said it counted only nine customers without central heat.

PPL staff members reach out to enroll customers in assistance programs in the months leading up to winter, said Paul Wirth, the utility's spokesman. Nils Hagen-Frederiksen, the PUC's spokesman, said the agency verifies PPL's count.

Peco has identified 886 of the customers without service who are eligible for federal heating grants and will be reaching out to them, said Ben Armstrong, a utility spokesman.

"We also know that 1,246 of these customers have a balance of $350 or less, and we will restore service to these customers upon their request," he said.

The utility law project said the survey understates the problem because it counts only customers of utilities regulated by the PUC, and it "does not reflect potentially thousands of other households without heat as a result of being unable to pay municipal, rural electric cooperative, propane, or oil bills."

215-854-2947 @maykuth