You can bet that the clear majority of boiler (or furnace) problems are due to improper installation. Those circumstances far outnumber bad equipment design.
It is critical for the near boiler piping to be done properly and according to the manufacturer recommended installation procedures. All boiler I&O manuals that I have seen include piping diagrams.
There may be requirements to dial in a condensing boiler with a combustion analyzer as part of the start up process.
Most I&O manuals are available for download. It would be advisable to review it, and make yourself informed of the installation procedures and to see if your current piping arrangement is good.
Although I do not work on boilers often, I have YET to see a properly installed residential cast iron boiler in my area. Fixing the piping errors is expensive.
Improper piping of almost any boiler will ruin it, and the chimney.