Sears installed our new high energy furnace in 2010 to replace our old furnace that was no longer approved to code. The new furnace required new vent pipes to meet the code brought in in 2007 (three years prior to installation). They installed new code standard vent pipe for the first three feet and then joined it on to the old pipe and then installed a piece of pipe on the outside to make it look as if the whole length of the pipe had been replaced. The old pipe is subject to cracking and leaking carbon monoxide (it is intended for plumbing and not hot gas venting)
This is possibly fraud in my view. Clearly they installed code approved pipe where you could easily see it at the furnace end and the outside wall and nothing between. It could have been fatal.
The furnace was inspected by the gas company on Friday and they issued a correction notice. If the venting pipe is not replaced to code within 45 days, our gas will be cut off until it is replace. Thank god it is not winter.