An inspection on old heating pipes that run 686 kilometers nationwide found 16 spots with safety risks, the Korea District Heating Corp. said Thursday.

An old hot water pipe burst near a subway station northwest of Seoul, killing one and injuring 45 on Dec. 4, prompting the KDHC to examine the hot water pipes that are more than 20 years old. Such pipelines account for 32 percent of the nation’s heating pipes that run a combined 2,164 kilometers in public areas.

In an inspection by 93 people using heat detection cameras, the KDHC found 203 spots with temperature differences in the pipelines and the surrounding area during the cold weather.

The state-funded company said it excavated five of the 16 spots with high safety risks due to large temperature differences and found that four had no problems.

“One area had minor leaks, so we replaced the pipeline,” the company said in a statement, adding that it plans to excavate the other 11 areas of possible risks.

As for the 443 pipeline segments that were built using the same technique used in the pipeline that cracked near Baekseok station last week, the KDHC said it has begun excavation work and plans to complete fixing or replacing them within this winter.

Apartment complexes in Seoul’s Mokdong, Yangcheon-gu, and Ansan’s Gojan-dong, which are not under the KDHC’s management, also had hot water pipe bursts in recent days.

By Kim So-hyun (sophie@heraldcorp.com)