Boiler flue/chimney question

A question about : Boiler flue/chimney question

It appears that the flue of the old oil boiler that is sited in the garage, goes through the garage wall and into the old chimney stack. (The original fires were removed years ago.)

It it likely that some sort of flue pipe will be carrying on inside the chimney (so any fumes etc will be contained) or will the flue itself end where it joins onto the chimney and the fumes are just being discharged via the chimney itself?

Best answers:

• Hi
  When we had our boiler installed years ago in the kitchen, the fitter sited it beside the old fire and the flu went up the chimney.... As there is no guarantee that the old chimney has no gaps in the bricks (hence any fumes could leak out into the house), the metal flu had to go right to the top of the chimney.. In fact, we could see the very tip of the flue at the top of the chimney, which had a metal cap on it to stop birds etc falling down it...
  Hope this helps..
  Regards