Honeywell RTH4300B Guide D'installation page 14

Installation Guide
Connect wires (typical installation)
1. Match each labeled wire with
same letter on terminal.
2. Use a screwdriver to
loosen screw terminals,
insert wires, then tighten
screws.
3. Push any excess wire back
into the wall opening.
Labels don't match?
If labels do not match letters on
thermostat, see next page.

Remove metal jumper if you
have both R and Rc wires.