My home was originally built in 1928. Newly remodeled in 2004. We moved in Sept. '04. With a new furnace being used throughout the winter season, my home had no chimney liner. A new chiney liner was installed in July this year. Was there a potential danger to my family, or no need to worry?
What was/is the furnace burning? Gas? Oil? Oil furnaces have been around for a long time, they used to be hooked into whatever chimney was available. Unlined, lined with ceramic, concrete, steel. For years they might even share the flue with wood-burners before that was outlawed. They changed the rules to avoid problems so I suppose there was a potential there, but I guess it turned out ok, so why worry now?