Gas and Oil Home Heating Furnaces - Furnace chamber

The other day my furnace would not start up so the guy from the oil company came, replaced the nozzle and told my wife that he was going to order some part but it should be fine until then. So, I dont think anything of it and then I get a call from them to schedule the appointment for the installation of the new chamber for my furnace. Hmm, chamber sounds fairly severe to me. So, Ive scheduled the appointment. So, I check the guys receipt that I got from the service call and sure enough it says under recommendations, 9-27076-chamber. Is the replacement of the chamber considered major surgery? Or is it not such a big deal. Im assuming its free under my service contract. Its an Intercity, Heil, 105.000 btu oil hot air furnace. Is the chamber as big a deal as the heat exchanger?

Many furnaces have a fiber insert that serves as a chamber liner. This is designed to reflect back heat for more thourough burning of the fuel.
The chamber liner looks like styrofoam.
This is pretty straightforward repair on a newer unit. If it's covered, then it's a home run. I would just check with the company to make sure.

Ok, I get it. So, its the chamber liner, not such a big deal. When I heard chamber I thought it was a major deal that might indicate that my whole furnace might be on its way out. Thanks for the reply.