A Spurious Connection message can appear when sizing pipework. This is usually due to a connection that is outside of a realistic scope, such as a return pipe joined to a section of the schematic that isn't connected correctly. This may also result in pipe sizes of 0mm.
On sizing, a spurious connection is detected at the indicated section (if the error is on another floor, the floor number and co-ordinates will be indicated).
1] Delete the return sections that connect into the section. This will enable us to size the rest of the system.
2] If you haven't turned on Section Numbers in the Default dialog, then do this now. This will help debugging the system.
3] Size the system, and then from the Notes menu, select to show all pipe sizes. Zoom into the are that is causing issue
The problem sections have no pipe number and are 'sized' at 0mm. This indicates that this whole section is not connected into the schematic, and is the cause of the Spurious Connection warning.
In this case, pipe number one had been drawn after the t section (H5, H6 and H7) and had been drawn over the junction, rather than connected to the junction. Delete pipe 1 and draw it back in correctly, ensuring you connect the junction up.
4] Add back in the return sections and re-size the system. This time it should work correctly.