On Thu, 3 May 2012 06:53:21 -0400, "Don Phillipson"
wrote:

"Bruce K." wrote in message
.. .

I was told that I couldn't convert my heating system to gas because

"my chimney won't tolerate the exaust heat"

I would appreciate any opinion on this.

This concerns fire safety. You can get specific information
(usually without charge) from the municipal building permits
office and/or the local fire brigade.
If it is good enough for an old oil furnace, adding a stainless
steel liner pipe will definitely make it safe for gas, heat-wize.