I would look at the possibility of using some
of the existing wire within the home, as suggested
by Ernie Bornn-Gilman on 02/11/04. I just Retro
installed a ZR-8630 with the spare 3 conductors
in the phone systems wiring, now it did mean that
the keypads ended up in odd locations(next to
the nightstand, above the counter in the galley,
etc. etc.)but it works. If you contact me or any
of the other guy's here in Tech Support at Niles,
yes we could explain to you how to make the Keypads
run on 3 conductors or even a 2 cond sheilded
!!