"BobtheTeacher" wrote in message
Can I add a "T" or "Y" pipe to my existing oil fired furnace stove
pipe just before it exits into the chimney? This would allow me to
vent the small wood stove up the same chimney flue the furnace and
H2O heater use.

What are your thoughts on this.

I"ve seen hacked jobs like that. Most (maybe all) codes require a flue for
each appliance. If the oil burner puts unburned fuel into the flue, your
woodstove could ignite them. Sort of like making your chimney into a jet
engine afterburner.