From February 17, travelers at Berlin Central Station will have to prepare for weeks of restrictions due to construction work.
As Deutsche Bahn announced on Friday, parts of the lower level of the main station will be closed for a good two months, until April 22. Instead of the eight tracks, only four tracks can be used alternately. Many regional trains will then be diverted or will not stop at the main station.
From March 21 to 24 and during the Easter holidays from April 18 to 22, a complete closure of the underground station is planned. Long-distance trains are scheduled to stop at other long-distance stations in Berlin on these weekends.
The reason for the closures is the construction of additional points and new signals in the main station. The company wants to reduce delays on the north-south connection.
During the construction work, there will also be timetable adjustments to regional services on the RE 3, RE 5, RB 14 and RB 23 lines as well as the Airport Express FEX. There will be detour with altered stops. The S-Bahn and the above-ground part of the station will not be affected.
Source: press release Deutsche Bahn in German language
https://www.deutschebahn.com/de/presse/pressestart_zentrales_uebersicht/Berliner-Hauptbahnhof-wird-leistungsfaehiger-mehr-Weichen-fuer-mehr-Verkehr-13285042
Recommendation:
Due to temporary connection detour and train cancellations during the work I recommend to re-check connections before journeys to / from Berlin via DB Navigator app and local public transport connections via BVG Fahrinfo-App.