
montasser charni
Hi ,from what I understand definitely a new boiler will need also a new flue system as it is against the regulations to fit a new boiler to an existing old flue . Also you've mentioned a vertical flue route in this case you will need to make sure that the flue is visible at every joint (here the need for inspection hatches if the flue is concealed). Last point a combination boiler connects to 5 pipes plus a condensate (plastic) pipe . Regards