My wife & I are currently thinking about remodeling our bathroom. Part of our remodel is moving the toilet 90 degrees to the left about 2 feet. Do I need to move the vent also or can the current vent be used?
The toilet flange should be connected to the 3" fixture arm with a long heel closet bend. The max length of the horizontal run of the 3" arm can vary depending on code. Trap weir to vent limit under UPC is 6' max, IRC is 12' max.
The IRC length is predicated on the horizontal run of 3" pipe being pitched at 1/4" per foot, because with IRC the bottom of the pipe at the trap weir can not be higher than the top of the pipe at the vent opening. So a 3" pipe divided by 1/4" pitch equals 12' of run before that happens.