Only know the year? We then use 1 January, which gives the earliest possible deadline.
The rule in §60b GModG
- Applies to heating systems with water as the heat carrier in buildings with at least six flats or other separate units.
- Installed before 1 October 2009: inspection by 30.09.2027.
- Installed later: inspection within a year after the system turns 15.
- Since July 2026 the Gebäudeenergiegesetz (GEG) has been called the Gebäudemodernisierungsgesetz (GModG). §60b keeps its number and content.
Not legal advice. The calculator does not account for exceptions under §60b, such as building automation or hydraulic balancing already carried out. Heat pumps fall under §60a with their own deadlines.
Source
§60b Gebäudemodernisierungsgesetz (GModG), gesetze-im-internet.de, read on 27.10.2026.
All buildings at once
A property manager has not one heating system but dozens. heizcheck works out the deadline for every system in your building list, sorts them by due date and collects the inspection reports from the installer through a link.