"Then I have an extension chord to my gas furnace to power the blower and furnace computer." is anyone else wondering how his home furnace has a regular plug?

"Then I have an extension chord to my gas furnace to power the blower and furnace computer." is anyone else wondering how his home furnace has a regular plug? aren't these things usually hard-wired with a dedicated circuit? you usually need a transfer-panel installed to do this.