Honeywell Home Round Smart Thermostat User manual

System Types
Compatible with 24-volt systems such as
forced air, hydronic, heat pump (including
dual fuel), oil, gas and electric.
Does not work with electric baseboard heat
(120/240V).
Must be installed by a trained, experienced technician
Read these instructions carefully. Failure to follow these instructions can
damage the product or cause a hazardous condition.
Mercury Notice:
If this product is replacing a control that
contains mercury in a sealed tube, do not
place the old control in the trash. Contact
the Thermostat Recycling Corporation at
18002388192 or thermostat-recycle.
org for information on how and where
to properly and safely dispose an old
thermostat.
Disconnect power before installation.
Can cause electrical shock or equipment
damage.
Round™ Smart Thermostat
Professional Install Guide
72

3
Also included:
“Getting Started” homeowner guide
AAA
AAA
Thermostat Wall plate
Anchors
Screws
Included in your box:
Optional wall cover
AAA

4
Installation
1 Insert the recommended wall anchors
It is recommended that you use the provided anchors when
mounting your thermostat.
Recommended drill bit size is 7/32 – 1/4-inch.
Optional: Attach the optional wall cover to the wall
plate
If you choose to use the optional wall cover to hide
blemishes, snap the wall plate to the optional wall cover
before continuing.
2 Bundle and insert wires through the clear
rubber holder
Guide the wires through the clear rubber holder on
the back of the wall plate.
Do not remove the clear rubber wire holder.

5
3 Set Jumper Switches
R Jumper Switch:
For single transformer
systems, move switch up.
For dual transformer
systems, move switch
down.
For single wire products,
set the switch to 1 Wire.
For two wire products,
set the switch to 2 Wire.
R(only)
RC (only)
RH(only)
R
RC
Set the R Jumper Switch Insert Wire(s) into Terminal(s)
RC
RH
R
Rc
R
Rc
R
Rc
R
Rc
R
Rc
R
R & RC
R
R & RC
R wire
Rc wire
RH wire
R wire
Rc wire
RH wire
Rc wire
Jumper Switch for humidifier, dehumidifier, or ventilation:

6
4 Connect all wires
Push each wire into its corresponding
terminal until it is firmly in place. Gently
tug on wires to verify they are secure. If
you misplace a wire, use a ballpoint pen to
push down on the terminals and release
the wire.
Refer to page 8 for wiring options,
configurations, and notes.
Note: The illustration to the right
shows the most common wiring
configuration.
5 Mount the wall plate using
the provided screws
AAA
AAA

7
6 Firmly snap the thermostat into place
The thermostat will glow and display the
screen for up to three minutes while it
starts up.

8
Wiring
Terminal Designations
LHeat pump system monitor KOptional C-wire adaptor
CCommon wire from secondary side of
cooling transformer, if 2 transformers
GFan relay
W2
(AUX)
2nd stage heat relay (heat pump
auxiliary, emergency heat)
Y2 2nd stage compressor contactor
W
(O/B)
1st stage heat relay (changeover valve
for heat pumps)
Y1st stage compressor contactor
U1 Terminal for indoor air quality products
(humidifier, dehumidifier, ventilator)
RHeating power. Connect to
secondary side of heating system
transformer
U2 Terminal for indoor air quality products
(humidifier, dehumidifier, ventilator)
Rc Cooling power. Connect to
secondary side of cooling
system transformer
Wiring Configurations
Two stage furnace and air-conditioning
CCommon wire (optional)
W2 Heat relay (stage 2)
WHeat relay
GFan relay
Y2 Compressor contactor (stage 2)
YCompressor contactor (stage 1)
RPower
Notes
• Thermostat Cwire
is optional for this
application. Cwire
required if Homekit
is used.
• Set the R Jumper
Switch on the wall
plate to R

9
Separate heating and cooling transformers
CCommon wire (optional)
WHeat relay
GFan relay
YCompressor contactor (stage 1)
RPower
Rc Power
Notes
• Thermostat Cwire
is optional for this
application. Cwire
required if Homekit
is used.
• Set the R Jumper
Switch on the wall
plate to R & Rc
Single stage heat pump with auxiliary heat (electric or dual fuel)
CCommon wire (optional)
AUX Auxiliary/Emergency heat
O/B Reversing valve
GFan relay
YCompressor contactor (stage 1)
RPower
Notes
• Thermostat Cwire
is optional for this
application. Cwire
required if Homekit
is used.
• Set the R Jumper
Switch on the wall
plate to R
Two stage heat pump with auxiliary heat (electric or dual fuel)
CCommon wire (optional)
AUX Auxiliary/Emergency heat
O/B Reversing valve
Y2 Compressor contactor (stage 2)
GFan relay
YCompressor contactor (stage 1)
RPower
Notes
• Thermostat Cwire
is optional for this
application. Cwire
required if Homekit
is used.
• Set the R Jumper
Switch on the wall
plate to R

10
Power open hot water zone valve
CCommon wire (optional)
WHeat relay
RPower
Notes
• Thermostat Cwire
is optional for this
application. Cwire required
if Homekit is used.
• Set the R Jumper Switch
on the wall plate to R
Two wire powered humidifier, dehumidifier, ventilator
U1 IAQ relay
U2 IAQ relay
Notes
• Set the Jumper
Switch on the wall plate to
2 Wire
Single wire non-powered humidifier, dehumidifier, ventilator, or
dehumidification with low speed fan
U1 IAQ relay Notes
• Set the Jumper Switch on
the wall plate to 1 Wire