Honeywell RCT8100 User Manual

Quick Installation Guide

RCT8100

Programmable Thermostat

Do you need assistance?

We are here to help.

Call 1-800-468-1502.

RCT8100 Programmable Thermostat

Installation is Easy

Your new thermostat has been designed for fast and
easy installation. Just follow the simple step-by-step
instructions in the following pages.

n Identify your system type.
o Remove your old thermostat.
p Identify the wires.
q Mount the new wallplate.
r Connect the wires.
s If the wire labels don’t match.

t Specify the furnace type.
u Install the batteries.
v Install the thermostat.
w Set the system.

1

Quick Installation Guide

n

This thermostat is compatible with the following
systems:

• Gas, oil or electric furnace

• Central air conditioner

• a hot water system with or without pump

• a millivolt system

• a central heating and cooling system

If you are not sure of your system type or if you have
any other questions, call us toll-free at 1-800-468-1502.

Identify System Type

This thermostat is not compatible with

heat pumps or multi-stage systems.

1.

2

RCT8100 Programmable Thermostat

o

1) Turn power off at the heating/cooling system.

2) Remove old thermostat, but leave wallplate with

Remove Old Thermostat

wires attached.

Do not remove wallplate yet.

MERCURY NOTICE: Do not put your old
thermostat in the trash if it contains mercury in a
sealed tube. Contact your local waste
management authority for instructions regarding
recycling and proper disposal.

2.

3

Quick Installation Guide

p

If any wires are not attached to your old thermostat or are
attached to a terminal marked C or C1, they will not be
connected to your new thermostat. Wrap the bare metal end
of each of these wires with electrical tape, so it cannot touch
and short other wires.

Identify Wires

Do not use
non-connected wires.

Do not use C or C1 wires

Identify and label each wire.

IGNORE WIRE COLORS:
Use terminal screw
designations to identify
wires.

Disconnect wires and remove the old wallplate only
after all wires are labeled. Wrap the wires around

a pencil to prevent them from falling though the
wall opening.

3.

4

RCT8100 Programmable Thermostat

q

1) Remove coverplate.

2) Loosen screw (the

3) Remove thermostat.

4) Mark and drill

Mount New Wallplate

screw remains
captive on wallplate).

appropriate mounting
holes (or use existing
holes). Insert plastic
anchors. Pass wires
through opening of
wallplate and secure

Labels don’t match?

wallplate to the wall

If a wire does not match any terminal on the thermostat,

using provided

see next page.

screws.

4.

5

Quick Installation Guide

r

1) Match each labeled wire with the terminal having

2) Loosen the terminal screws using a screwdriver,

3) Push any excess wire back into the wall opening.

Connect Wires (typical wiring)

Remove jumper
if you have both
R and Rc wires.

the same letter.

insert the wires, then tighten the screws.

5.

6

RCT8100 Programmable Thermostat

s

If a labeled wire does not match any terminal
designation, see diagram below.

Connect Wires (less common wiring)

Do not use C, X or B. Wrap bare end of wire
with electrical tape.

If wires are connected to both Rh and Rc
terminals, remove jumper (see previous
page).

7