Some Pacific Gas and Electric Co. SmartMeters can overcharge customers when they become too hot.
Officials said on Monday that almost 1,600 of the wireless electricity and gas meters across Northern and Central California were found to be affected by the defect.
They sometimes misread electricity usage when their internal temperature goes over 100 degrees.
PG&E officials tell the San Francisco Chronicle they have replaced or will replace the defective meters. Affected customers will also receive refunds averaging $40 as well as a $25 credit.
The digital SmartMeters are used by many utilities across the country. PG&E has installed nearly 8 million and has plans for another 2 million.