Size and hight of the chimney? clay lined? "B" vent? BTU's of water heater? Got a gas liscence ? Chances are you will need a stainless steel liner because the existing vent will be too large. Consider the age of your water heater.If you think it will need to be replaced in the near future ,maybe you should replace it with a power vented unit, and do away with the chimney all together. Just a thought
It is a B vent chimney and I would estimate the height at about 30ft. The existing hot water heater is only 2 years old so we really don't want to replace it.
Are there any safety issues with using the chimney vent for the hot water heater and switching to a pvc vent for the furnace?