1) GE 15086 is not a 3-way timer.
GE programmable timers are for single-pole switch replacement only. I have tested this timer, and own several GE timers, and many other brands.
2) Open following link to identify timers that work for 3-way switching.http://waterheatertimer.org/GE-timers-and-manuals.html#15071
3) After buying correct timer, then you need to review wiring diagrams carefully because the timer replaces 1 of the 3-way switches, but other 3-way switch has to be wired exactly right to match your brand of timer.
4) Links on page above show manuals for each of the 3-way timers. Compare wiring for each timer with Intermatic wiring that you are replacing, because Intermatic is wired differently than Aube.
5) Or just buy another Intermatic ST01C or EJ500 or EI400, etc, and wiring with change out 1 for 1.
6) Add a comment for more free help.
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