I believe it's city water and believe it's relatively hard but regardless it only seems to affect the injector I've not had issues with my boiler checks even though I do clean them as well post run just to make sure. I too am now doing what NP317 suggests and fill with air and blow out the injector line.
But I've become so sensitized to not having my injector work once she's breathing on her own that I just clean it anyway....
Ken-
Super scale economy injector question
Re: Super scale economy injector question
a superscale injector that doesn't pull air, or have dirt in it, should be a very reliable method of feed water supply.