This thermostat provides electronic control of 24 VAC heat pump systems with auxiliary heat (2 heat/1 cool).
Power Type
•Battery power
•Common wire
•Common wire with battery backup
System Settings
•Heat, Off, Cool, Em Heat
Fan Settings
•Auto, On
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.
•Check the ratings in this booklet to verify that this product is suitable for your
application (see page 12).
•Always test for proper operation after installation (see pages 7-8).
CAUTION: ELECTRICAL HAZARD
Can cause electrical shock or equipment damage. Disconnect power before
beginning installation.
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 your local waste management authority for
instructions regarding recycling and proper disposal.
Install the thermostat about 5 feet (1.5m) above the floor in an area
with good air circulation at average temperature.
Appppeennddiicceess
A
Adaptive Intelligent Recovery ........9
Compressor protection ..................9
Quick reference to controls..........10
Quick reference to display ............10
In case of difficulty ......................11
Accessories....................................12
Specifications ................................12
NO
NO
Do not install in locations where the thermostat can be affected by:
• Drafts or dead spots behind doors and in corners
• Hot or cold air from ducts
• Sunlight or radiant heat from appliances
• Concealed pipes or chimneys
• Unheated/uncooled areas such as an outside wall behind the thermostat
NO
1
Page 4
Installation Guide
Pre-installation checklist
Package contents
Check to make sure your package includes the following items:
•PRO TH4210D digital thermostat (wallplate attached to back)
•Operating manual
•Wall anchors and mounting screws (2 each)
•AA alkaline batteries (2)
•Quick reference card
Required tools & supplies
•No. 2 Phillips screwdriver
•Small pocket screwdriver
•Drill
•Drill bit (3/16” for drywall, 7/32” for plaster)
•Hammer
•Pencil
•Electrical tape
•Level (optional)
2
Page 5
PRO TH4210D Programmable Thermostat
Wallplate installation
Grasp top and bottom of wallplate
and pull to remove from thermostat.
Remove the wallplate from the thermostat as shown at left, then follow
directions below for mounting.
1Pull wires through wire hole.
2Position wallplate on wall, level and
mark hole positions with pencil.
3Drill holes at marked positions as
shown below, then tap in supplied
wall anchors.
4Place wallplate over anchors, insert
and tighten mounting screws.
5Insert quick reference card in slot
in front of wall plate.
Drill 3/16” holes for drywall.
Drill 7/32” holes for plaster.
Wall anchors
Insert quick reference card after
wallplate is mounted (see mounting
instructions, below)
Mounting screwsWire hole
3
Page 6
Installation Guide
Wiring
CAUTION: ELECTRICAL HAZARD. Can cause electrical shock or equipment damage.
Disconnect power before wiring.
Keep wires in this
shaded area
Terminal
block
Wiring
1Loosen screw terminals, insert
wires into terminal block, then retighten screws.
2Push excess wire back into the
wall opening. Keep wires in shaded
area as shown at left.
3Plug the wall opening with non-
flammable insulation to prevent
drafts from affecting thermostat
operation.
Terminal Designations
E
E
Emergency heat relay.
NOTES
C terminal
The C (common wire) terminal is optional
when thermostat is powered by batteries.
L terminal
Heat pump reset. L terminal is powered continuously when thermostat is set to Em Heat.
Wire specifications
Use 18- to 22-gauge thermostat wire.
Shielded cable is not required.
A
Auuxx
Y
Y
G
G
O
O
L
L
R
R
B
B
C
C
Auxiliary heat relay.
Compressor contactor.
Fan relay.
Heat pump changeover valve
energized in cooling.
Heat pump reset.
Power wire from secondary
side of system transformer.
Heat pump changeover valve
energized in heating.
Common wire from secondary
side of system transformer.
4
Page 7
PRO TH4210D Programmable Thermostat
Wiring diagram
1Power supply. Provide disconnect means and overload protection as required.
2Optional 24 VAC common connection.
3Use either O or B terminals for changeover valve.
4L terminal is powered continuously when thermostat is set to Em Heat.
5Install field jumper between E and Aux if there is no emergency heat relay.
5
Page 8
Installation Guide
Power options & mounting
Connect common
side of transformer
to “C” terminal
AC Power
The thermostat can be powered by 24
VAC power, or by batteries.
To wire the thermostat for AC power,
connect the common side of the
transformer to the “C” terminal as
shown at left.
Install batteries in back of thermostat
(optional if AC powered).
Battery Power
The thermostat can be powered by
batteries alone or, if used with AC
power, can provide backup power.
During power interruptions the
batteries will save time/day settings
and power the display.
To Mount Thermostat
Align the 4 tabs on the wallplate with
corresponding slots on the back of the
thermostat, then push gently until the
thermostat snaps in place.
6
Page 9
PRO TH4210D Programmable Thermostat
Installer setup
Follow the procedure below to configure the thermostat to match the installed
heating/cooling system, and customize feature operation as desired.
Press and hold both buttons
Function
number
To begin, press and hold the and
buttons until the display changes
Press to change settings
Press to advance to next function
Pr
Setup FunctionSettings & Options
6
Auxiliary heat
cycle rate
(CPH: cycles/hour)
5 For gas or oil furnaces of less than 90% efficiency
1For steam or gravity systems
3For hot water systems & furnaces of over 90% efficiency
9For electric furnaces
After completing the installer setup above, press the button again to begin a
system test (see next page).
7
Page 10
Installation Guide
Installer system test
Follow the procedure below to test the heating and cooling system.
System test
number
10
System switch
S
1Set
2Press to turn on and check systems (see table, below).
3Press until systems turn off.
4Set
5Set
SYYSSTTEEMM
S
SYYSSTTEEMM
SYYSSTTEEMM
S
switch to Heat
switch to Em Heat
switch to Cool
.
and repeat steps 2-3 above.
and repeat steps 2-3 above.
System status
0
Test
5Press and holdto terminate test at any time.
System TestSystem Status
10
Heating system
20
Emergency heat
30
Cooling system
70
Thermostat
information
(for reference only)
0Compressor and fan turn off.
1Compressor and fan turn on.
2Auxiliary heat turns on.
0Heat and fan turn off.
1Heat and fan turn on.
2Auxiliary heat turns on.
0Compressor and fan turn off.
1Compressor and fan turn on.
71 Software revision number (major revisions)
72 Software revision number (minor revisions)
73 Configuration identification code (major)
74 Configuration identification code (minor)
75 Production configuration date code (week)
76 Production configuration date code (year)
CAUTION: EQUIPMENT DAMAGE HAZARD
Compressor protection (minimum off time) is bypassed during testing. To prevent
equipment damage, avoid cycling the compressor quickly.
8
Page 11
PRO TH4210D Programmable Thermostat
Adaptive Intelligent Recovery™(Setup Function 13)
Adaptive Intelligent Recovery eliminates guesswork when setting your schedule.It
allows the thermostat to “learn” how long your furnace and air conditioner take to
reach the temperature you want.
Just set your program schedule to the time you want the house to reach your
desired temperature.The thermostat then turns on the heating or cooling at just the
right time to reach your scheduled temperature at your scheduled time.
For example:Set the Wake time to 6 am, and the temperature to 70°.The heat will
come on bef
ore 6 am, so the temperature is 70° by the time you wake at 6.
Built-in compressor protection (Setup Function 15)
This feature helps prevent damage to the
InsideSet To
compressor.
°
75
Wake
Wed
Message flashes until safe
restart time has elapsed
6:30
AM
75
Cool
On
°
Damage can occur if the compressor is restarted too soon after shutdown.This feature
forces the compressor to wait for a few minutes before restarting.
During the wait time, the message Cool On
or Heat On will flash on the display.When
the safe wait time has elapsed, the message
stops flashing and the compressor turns on.
9
Page 12
Installation Guide
Quick reference to controls
Temperature adjustment
Fan switch
On: Fan runs continuously.
Auto: Fan runs only when heating
or cooling system is on.
•Set: Press to set time/day/
schedule
•Hold: Press to override
programmed temperature control.
•Run: Press to resume program
schedule
System switch
•Cool: Thermostat controls only
the cooling system.
•Heat: Thermostat controls only
the heating system.
•Off: Heating and cooling
systems are off.
•Em Heat: Thermostat controls
emergency and auxiliary heat.
Compressor is locked out.
Quick reference to display screen
Low battery warning Adaptive Intelligent Recovery
Current inside
temperature
Current program period
Wake/Leave/Return/Sleep
Replace Batt
InsideSet To
Recovery
°
75
Wake
6:30
Wed
Current day/time
AM
75
Em Aux
Heat
On
Temperature setting
System status
Em: Emergency heat on
°
Aux: Auxiliary heat on
Heat On/Cool On:
(Flashes when waiting
for compressor restart)
10
Page 13
PRO TH4210D Programmable Thermostat
In case of difficulty
If you have difficulty with your thermostat, please try the suggestions below. Most
problems can be corrected quickly and easily.
Display is blank•Check circuit breaker and reset if necessary.
•Make sure heating & cooling power switches are on.
•Make sure equipment door is securely closed.
•If battery powered, make sure fresh AA alkaline batteries are installed.
Temperature
settings do not
change
Heating system
does not respond
(“Heat On”
appears on
screen)
Cooling system
does not respond
(“Cool On”
appears on
screen)
Make sure heating and cooling temperatures are set to acceptable ranges:
•Heat: 40° to 90°F (4.5° to 32°C).
•Cool: 50° to 99°F (10° to 37°C).
•Check for 24 Vac at the equipment on the secondary side of the transformer between power and common. If voltage is not present, check the
heating equipment to find the cause of the problem.
•Check for 24 Vac between the heat terminal (Y) and the transformer
common. If 24 Vac is present, the thermostat is functional. Check the
heating equipment to find the cause of the problem.
•Check for loose or broken wires between the thermostat and the heating
equipment.
•Check for 24 Vac at the equipment on the secondary side of the transformer between power and common. If voltage is not present, check the
cooling equipment to find the cause of the problem
•Check for 24 Vac between the cooling terminal (Y) and the transformer
common. If 24 Vac is present, the thermostat is functional. Check the
cooling system to find the cause of the problem.
“Cool On” or
“Heat On”
is flashing
“Heat On” is
not displayed
“Cool On” is
not displayed
•Check for loose or broken wires between the thermostat and the cooling
equipment.
•Compressor protection timeout is engaged. Wait 5 minutes for the
system to restart safely, without damage to the compressor.
•Set the System switch to Heat
current room temperature.
•Set the System switch to Cool
current room temperature.
, and set the temperature level above the
, and set the temperature level below the
11
Page 14
Installation Guide
Accessories
Please contact your distributor to order accessories.
Cover plate assembly ............................................Part Number 50002883-001
(Used to cover marks left by old thermostats.)
Specifications
Temperature Ranges
•Heat: 40° to 90°F (4.5° to 32°C)
•Cool: 50° to 99°F (10° to 37°C)
Operating Ambient Temperature
•32° to 120°F (0° to 48.9°C)
Shipping Temperature
•-20° to 120°F (-28.9° to 48.9°C)
Operating Relative Humidity
•5% to 90% (non-condensing)
Physical Dimensions
•3-13/16” H x 5-3/8” W x 1-1/4” D
•97 mm H x 137 mm W x 32 mm D
Electrical Ratings
SystemVoltage (50/60Hz)Running Current
Heat (1ststage)20-30 Vac0.02-1.0 A
Emergency heat20-30 Vac0.02-1.0 A
Auxiliary heat20-30 Vac0.02-1.0 A
Cooling20-30 Vac0.02-1.0 A
12
Page 15
Page 16
Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario M1V 4Z9
http://yourhome.honeywell.com
Printed in U.S.A. on recycled
paper containing at least 10%
post-consumer paper fibers.