Honeywell RTH3100C User manual

Owner’s Manual
Read and save these
instructions.
For help please visit
yourhome.honeywell.com
RTH3100C
Non-Programmable
Digital Thermostat
Installation is Easy
1. Label wires and remove your old thermostat
2. Install and wire your new thermostat
3. Set your new thermostat to match your heating/cooling system
Do you need assistance? We are here to help.
Call 1-800-468-1502 for wiring assistance before returning
the thermostat to the store.
For use with Heat Pump Systems ONLY.

2
M28333
NOTICE: To avoid possible compressor damage, do not run air
conditioner if the outside temperature drops below 50°F (10°C).
ATTENTION: MERCURY RECYCLING NOTICE
This product does not contain mercury. However,
this product may replace a product that contains
mercury. Mercury and products containing
mercury should not be discarded in household
trash.
For more information on how and where to
properly recycle a thermostat containing
mercury in the United States, please refer to the
Thermostat Recycling Corporation at
www.thermostat-recycle.org.
For mercury thermostat recycling in Canada,
please refer to Switch the Stat at
www.switchthestat.ca
NO MERCUR
Y
NO BOTE
MERCURIO
Hg
Customer assistance
For assistance with this product, please visit
http://yourhome.honeywell.com.
Or call Honeywell Customer Care toll-free at
1-800-468-1502.
To save time, please note your model number
and date code before calling.
Pull at bottom to remove thermostat from
wallplate.
Turn thermostat over to find model number
and date code.
® U.S. Registered Trademark. Patents pending.
M28331

3
Installation
Installation............................................3
System Setup.......................................8
About your new thermostat
Controls................................................9
Home screen quick reference ............10
Programming and operation
Compressor protection.......................10
Replace batteries ...............................11
Accessories/replacement parts..........11
Appendices
Troubleshooting..................................12
Limited warranty.................................13
Table of contents
1 Turn Off Power to Heating/Cooling System
or
M31535
Circuit breaker
box Heating/cooling system power switch

4
Do not remove wallplate yet
3 Label Wires with Tags
Label the wires using the supplied wire labels as you disconnect them. If any
wires are not attached to terminals in your old thermostat, do not connect them
to your new thermostat.
Wrap the bare metal ends of each unused wire with electrical tape, so it cannot
touch and short out other wires.
Wire Labels
M28100
C
C
MCR33823
Terminal
designation
If you have an older thermostat with a
sealed mercury tube, turn to page 2
for proper disposal instructions.
Terminal designation
C
C
MCR31537
2 Remove Old Thermostat
Remove old thermostat but leave wallplate with wires attached.
4 Separate Wallplate from
New Thermostat
Remove wallplate from the new thermostat
and mount onto wall.
Wallplate

5
5 Mount Wallplate
Mount the new wallplate using the included screws and anchors.
Drill 3/16-in. holes for drywall
Drill 3/32-in. holes for plaster
6 Connect Wires
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.
If labels do not match letters on the thermostat, check “Alternate Wiring” on page
6and connect to terminal as shown (see notes, below).
We are here to help. Call 1-800-468-1502 for wiring assistance.

6
Alternate Wiring
If the old thermostat had both Vand VR wires, contact a heating/cooling
contractor for help.
If the old thermostat had both Oand Bwires, attach the Bwire to the C
terminal. If another wire is attached to the Cterminal, call 1-800-468-1502
for help.
If the old thermostat had W1, W2 and Ywires, contact a heating/cooling
contractor for help.
If no wire matches the Eterminal on the new thermostat, use a small
piece of wire to connect terminals Eand Aux.
Aux YGOL
RBC
E
Aux YGOLRBCE
43321 2 2
or
X
X2
or
W
W1
W2
or
Y1
M
or
F
or
F
or
V
VR
or
H
or
B
X
7 Install Batteries
Install two AA alkaline batteries.
Back of thermostat

7
8 Install Thermostat onto
Wallplate
Install thermostat onto the wallplate on
the wall.
9 Turn Power Back On
Turn the power back on to
the heating/cooling system.
M31544
or
Circuit breaker box Heating/cooling system
power switch

8
System Setup
Enter System Setup
Next, you must set the thermostat to control the heating and cooling system in
your home. To enter system setup, press and hold both the sand tbuttons
until the display changes (approximately 5 seconds).
Changing Settings
1. Press tto change the setting.
2. Press sto advance to the next function.
3. Press and hold sand t to exit and save settings.
Function
Description
Press the tbutton to Setting
6 select your auxiliary heating
system and optimize its
operation
3 Heat pump
8 select your emergency heating
system and optimize its
operation
9 Electric furnace: Use this setting if you have any type of
electric heating system.
14 select Fahrenheit or Celsius
temperature display
0 Fahrenheit temperature display (°F)
1 Celsius temperature display (°C)
Setup
6
5
Function
Setting

9
About your new thermostat
Your new Honeywell thermostat has been designed to give you many years of
reliable service and easy-to-use, push-button climate control.
• One-touch temperature controls
• Large, clear backlit display is easy to read, even in the dark
• Switchable fan control (auto or continuous fan)
• Displays both room temperature and temperature setting
• Built-in compressor protection
Thermostat controls
M28327
Digital display
screen Temperature adjustment
Press the up or down
buttons until you
reach the desired
temperature.
NOTE: Make sure the
SYSTEM switch is set to
the system you want to
control (Heat or Cool).
Fan Switch is used to
control your fan.
In “Auto” mode, the fan
runs only when the heating
or cooling system is on.
If set to “On,” the fan runs
continuously.
System Switch is used to control your
heating or cooling system.
• Cool: Cooling system control.
• Off: All systems off.
• Heat: Heating system control.
• Em Heat: Emergency & Auxiliary Heat
control. Compressor is locked out.

10
Heat On
Set ToInside
75
75
Replace Batt
M28328
Low battery
warning
(see page 11)
Current inside temperature Temperature setting
System status
Cool on: Cooling system is on.
Heat on: Heating system is on.
Em: Emergency heat is on.
Aux: Auxiliary heat is on.
When Cool On/Heat On is flashing, compressor protection is engaged (see
page 10).
Display screen
Built-in compressor protection
This feature helps prevent damage to
the compressor in your air conditioning
or heat pump system.
Damage can occur if the compressor is
restarted too soon after shutdown. This
feature forces the compressor to wait 5
minutes before restarting.
During the wait time, the display will
flash the message Cool On or Heat On.
When the safe wait time has elapsed,
the message stops flashing and the
compressor turns on.
Cool On
Set ToInside
75
75
M28330