Signal problems on two lines, a faulty door on a train servicing two others and steam coming from the track of another all conspired to create delays for Metro commuters heading to work Monday morning.

The worst headache was on the Red Line. Just before 7 a.m., a train operator reported steam coming from an insulator on the outbound track between the Grosvenor and Medical Center stops.

The insulator is a piece of equipment that keeps electricity on the third rail from other parts. If a bolt, or other part, on the insulator is loose, or there is some other problem with the insulator, smoke can form along the track.

Metro stopped service in the troubled area and trains had to share the inbound track, creating delays of up to 30 minutes or more for some commuters in the morning rush hour. Trains also alternated turning around at Medical Center so they could service riders at the Silver Spring end of the Red Line.

It took Metro nearly seven hours to make repairs.

Metro spokesman Dan Stessel said the agency decided to wait until 10 a.m. to bring in lighting, cables, cranes and other repair materials from the Shady Grove railyard so as not to exacerbate the “already lengthy delays” for commuters.

By noon, Metro said it was working to replace power cables and 20 insulators.

That area on the Red Line is well known to Metro engineers for having trouble.

“If it is humid or water is dripping or it is a wet or moist environment that can cause an electrical current to deviate from the proper path,” Stessel said. “That can cause arcing, a short circuit and other issues.”

Metro has had other troubles with insulator equipment. In January, riders aboard a Green Line train exited on their own after they were stranded near the Anacostia stop.

There also was a report of a “downed track circuit” on the Green Line outside the Southern Avenue stop, something Stessel called a “fairly routine issue.” Crews reset the circuit and two trains were each delayed 10 minutes, he said.

There were also 20-to-30-minute delays for riders on the Orange Line because of a signal problem at Vienna. And riders on a Yellow Line train bound for Huntington had to get off at the Braddock Road stop because of a door problem that caused some minor delays on the Blue and Yellow lines.

It is the second time in three weeks that all five of Metro’s rail lines have had issues on the same day.

In an e-mail, Stessel said that the troubles on Metro’s lines Monday were not a result of any recent weekend track work. He also summed up the Monday morning delays.

“There have been delays worth noting on the Red and Orange” lines, he said in an e-mail. “The other issues were the minor rigmarole of any AM commute.”