This might be a bit of a convoluted write-up, but - I would like to convert 2 different outside lights (referred to below as ‘patio’ and ‘backyard’) to smart switches (Zooz ZEN26). Each of the lights consists of 2 CFL Flood bulbs of 23 watts each. Each of the 2 lights is on a set of 3-way switches. Complicating this is that both sets of 3 ways are not functioning quite right with the old dumb switches. The switches are in 3 different switch boxes - Box #1 has 4 switches in 3 gangs (I believe both smart switches will end up in this box). Box #2 has 2 switches in 2 gangs, and Box #3 has 1 switch in 1 gang.
Summary of how the old, dumb 3-way switches currently function:
Box #1-down > Box #2-up > light OFF
Box #1-down > Box #2-down > light OFF
Box #1-up > Box #2-down > light ON
Box #1-up > Box #2-up > light OFF
Box #1-left > Box #3-up > light ON
Box #1-left > Box #3-down > light ON
Box #1-right > Box #3-down > light OFF
Box #1-right > Box #3-up > light ON
In order to fix the Patio light switches so that the light is properly toggled when either switch is flipped, I believe all I need to do is move the black wire from ‘A’ to the currently unused screw terminal.
As for the backyard light - I am stumped as to why that set of switches isn’t properly toggling the light.
Once I have verified that the old dumb switches have been fixed to operate properly, I will re-arrange the switches in Box #1 when I install the smart switches. I will also be replacing all of the other, unrelated dumb switches with new ones (they’re all old and discolored). The Patio 3-way switch will be swapped places with the 3-way switch labeled as Office Outlet, which will allow one full gang for each of the new smart switches. Dumb switches will be on the double switch.
B (or F?) - goes go Breaker #20
F (or B?) - goes to Office Outlets (just a guess)
I - This probably goes to the backyard light fixture, but I’m not sure why the outside sunroom light would be tied off this wire.
Diagrams of the current wiring: