Pepco plans to continue installing new electric meters in customers' houses, although the meters have overheated and caught fire in the Philadelphia area, the Washington-area utility said Tuesday.

The Maryland Public Service Commission heard testimony from Pepco, Baltimore Gas and Electric Co. and the Southern Maryland Electric Cooperative on Tuesday after two of PECO's 186,000 smart meters caught fire and 13 others overheated in the Philadelphia area.

Of the 15 incidents, six were caused by existing issues with customers' equipment, said spokeswoman Cathy Engel Menendez. The other nine are still under investigation.

Though 15 of Pepco's 300,000 smart meters have had incidents in which they alerted the company to a higher-than-desired temperature, none resulted in a fire or other damage, said Pepco spokeswoman Courtney Nogas.

Though PECO has halted installation of the meters while it investigates, Pepco has no plans to stop using them.

There's a risk of a meter overheating anytime a new one is installed, whether it's one of the new smart meters that provide constant communication with the electric company or an older model, Karen Lefkowitz, Pepco Holdings' vice president of business transformation, told the Public Service Commission.

"Once you remove an old meter, you may be discovering that there's some corrosion there. It's been exposed to the elements for, in some cases, 30 years, and so now when you're plugging in that new meter, you're creating an opportunity for a short and for something to be misaligned," she said.

Smart meters also have an advantage over older meters in their temperature sensors, which allow monitoring from afar, said BGE Smart Grid Director Michael Butts. With an old meter, the only way to discover the cause of a malfunction is to visit the meter.

But Maryland Del. Glen Glass, R-Harford and Cecil counties, said the fires are a reason to abandon the smart meters.

He was already concerned about the health hazards of the meters' electromagnetic fields and radio frequencies -- though those risks have been discredited by multiple government agencies.

"They should just be banned altogether, but Marylanders should at the very least be given a choice to permanently opt-out from having a smart meter installed," Glass said.

Update Aug. 30: Pepco does not use the same brand of smart meters as Philadelphia's PECO.