Metro had tried a number of fixes for the shared chiller equipment for busy Farragut North and Dupont Circle stations without success, before finally beginning more significant repair work late last year.

A permanent cooling system is expected to flip back on at two Red Line stations soon for the first time in years.

Metro had tried a number of fixes for the shared chiller equipment for busy Farragut North and Dupont Circle stations without success, before finally beginning more significant repair work late last year.

“It’s moving along,” Metro General Manager Paul Wiedefeld said. “We’re pushing real hard to get that….finalized for summer,” he said.

Metro typically flips on its chiller systems at all underground stations in mid-May.

It is not yet certain whether work that has included a long-term lane closure on Connecticut Avenue NW north of K Street will be completed by then, but Metro does expect the cooling systems will be activated before summer heat ramps up.

There have been no major issues with the work, Wiedefeld said.

The chiller system has been broken at the two stations since at least 2015. The systems work by circulating water through a cooling tower before returning it through the stations to keep temperatures somewhat lower than the temperature outdoors.

Metro initially tried in 2015 and 2016 to repair some individual leaks in those water pipes and to reline the pipes under Connecticut Avenue NW, but it was not enough to get the system working.

In 2017, Metro began to look at a complete replacement of the pipes and, in the meantime, installed a temporary cooling tower at street level in both 2017 and 2018.

Farragut North and Dupont Circle stations are original parts of the Metro system, opening 1976 and 1977 respectively, and Metro said the pipes had not been replaced in more than 40 years. Metro is also in the process of a broader project to replace chiller systems at other stations.