Honeywell RTHL2510 series User manual

Owner’s Manual
Read and save these
instructions.
RTHL2510/RTHL2410
Series
Programmable
Thermostat
Identify System Type
This thermostat is compatible with the following systems:
•Gas, oil or electric furnace
•Central air conditioner
•Hot water system with or without pump
•Millivolt system
•Central heating and cooling system
•Heat pump without auxiliary/backup heat
•Heat pump with auxiliary/backup heat

2
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.
NO MERCUR
Y
Hg
RTHXXXX
M32707
Customer assistance
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.

3
Installation
Installation............................................3
Advanced Installation...........................9
About your new thermostat
Controls and Home screen
quick reference...................................11
Preset energy-saving schedules........12
Programming and operation
Setting the clock.................................12
Adjusting program schedules.............13
Overriding schedules temporarily ......14
Overriding schedules permanently ....14
Compressor protection.......................15
Early Start ..........................................15
Replace batteries ...............................16
Appendices
Troubleshooting..................................17
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.
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.
M32731
TO REMOVE WALLPLATE
PULL HERE
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
Simply match wire labels.
If labels do not match letters on the thermostat, check “Alternate Wiring
(Conventional Systems)” on page 6 and connect to terminal as shown (see
notes, below).
M32715
SCREW
INSERT WIRES
AND TIGHTEN
SCREWS
WIRE
HOLE
LABELED
WIRES
W/
Aux
W
Y
G
R
Not
Used
Remove metal
jumper if you
have both Rand
Rc wires.
W/
Aux
Not
Used
M32714

6
Alternate Wiring (Conventional Systems)
If labels do not match letters on the thermostat, check the chart below and
connect to terminal as shown here (see notes, below).
If wires will be connected to both Rand Rc terminals, remove metal
jumper.
Do not use Cor X. Wrap bare end of wire with electrical tape.
If you have a heat pump without auxiliary/backup heat connect Oor B,
not both. If you do not have a heat pump, do not connect B. Wrap bare
end of wire with electrical tape.
Place a jumper (piece of wire) between Yand Wif you are using a heat
pump without auxiliary/backup heat.
B O G Y
W/
AUX
NOT
USED
R Rc
M32726
44
M32727
GW/
AUX
OBY
Y
G
O
R
R
Rc
Aux
Alternate Wiring (Heat Pump)
If labels do not match letters on thermostat, see page 7.

7
7 Install Batteries
Install two AAA alkaline batteries.
Back of thermostat
RTHXXXX
M32707
Alternate wiring (for heat pumps with auxiliary or backup heat only)
If labels do not match letters on the thermostat, check the chart below and
connect to terminal as shown here (see notes, below).
Leave metal jumper in place, connecting R& Rc terminals.
If your old thermostat had both Vand VR wires, stop now and contact a
qualified contractor for help.
If your old thermostat had separate Oand Bwires, wrap the B wire in
electrical tape and do not connect.
If your old thermostat had Y1, W1 and W2 wires, stop now and contact a
qualified contractor for help.
Do not use Cor Xwire. Do not use Bwire if you already have Owire.
Wrap bare end of wire with electrical tape.
Do not use Lwire. Wrap bare end of wire with electrical tape.
If your old thermostat had Eand Aux wires (or alternate wires), connect
both wires to Aux terminal.
5
6
7
M32728
2
7
4
AUX
W
W1
W2
F
BOG
H
C
RC
V
VR
B
X
R
M
Y1
Y
E
7
X
X2
L
F
6532
1
B O G Y
W/
AUX
NOT
USED
R Rc

8
8 Set fan operation switch
Move the switch to the proper setting:
Gas or Oil: For gas or oil heating systems,
leave the fan operation switch in this factory-set
position (for systems that control the fan in a call
for heat).
Electric or Heat Pump: Change the switch
to this setting for heat pump or electric heat
systems. (This setting is for systems that
allow the thermostat to control the fan in a call
for heat, if a fan wire is connected to the G
terminal.)
9 Install Thermostat onto
Wallplate
Install thermostat onto the wallplate on
the wall.
RTHXXXX
M32716
GAS OR OIL
ELECTRIC OR HEAT PUMP
GAS OR OIL
ELECTRIC OR HEAT PUMP
10 Turn Power Back On
Turn the power back on to
the heating/cooling system.
W/
Aux
Not
Used
Heat Off Cool Auto On
Fan
M32705
M31544
or
Circuit breaker box Heating/cooling system
power switch

9
11If your system type is...
If your system type is:
qSingle Stage Heat and Cool
qHeat Only or Cool Only
Congratulations, you’re done!
If your system type is:
qHeat Pump* with Backup Heat
Continue with Advanced Installation to match your thermostat to your system
type.
*Heat Pump—an air conditioner that provides cooling in the summer, and also
runs in reverse in the winter to provide heating.
This thermostat works on 24 volt or 750 mV systems. It will NOT work on multi-
stage conventional systems.
Advanced Installation
Enter System Setup
To enter system setup, press and hold
both the sand tbuttons until the display
changes (approximately 5 seconds).
Changing Settings
1. Press the sor tbutton to change
the setting.
2. Press the sand tbuttons
simultaneously for one second to
advance to the next function.
3. Press the RUN button to exit and save
settings.
M32713
Heat Off Cool Auto On
Fan
Function
Setting
55
M32779

10
NOTE: If you do not press any button for 60 seconds while you are in the setup
menu, the thermostat automatically saves any changes made and exits the
menu.
Function
Description
Press the sor tbutton to Setting
1 select system type 0 Heating & cooling: Gas, oil or electric heating with central
air conditioning or heat pump without auxiliary/back-up heat.
1 Heat pump with auxiliary/backup heat: Outside
compressor provides both heating and cooling.
5 select your heating system and
optimize its operation
5 Gas or oil furnace: Use this setting if you have a standard
gas or oil furnace that is less than 90% efficient.
6 Electric furnace: Use this setting if you have any type of
electric heating system.
3 Heat pump, hot water or high-efficiency furnace:
Use this setting if you have a hot water system or a gas
furnace of greater than 90% efficiency.
2 Gas/oil steam or gravity system: Use this setting if you
have a steam or gravity heat system.
13 select Early Start 1 On
0 Off
14 select Fahrenheit or Celsius
temperature display
0 Fahrenheit temperature display (°F)
1 Celsius temperature display (°C)
15* select Compressor Protection
settings
1 On
0 Off
20 select clock display 0 12-hour display
1 24-hour display
40 restore program schedule to
default settings
0 Off
1 On: Program schedule default settings are listed on
page12.
* Compressor Protection: This feature forces the compressor to wait approximately 5 minutes before
restarting, to prevent equipment damage. During the wait time, the message “Cool On” or “Heat On”
is displayed on screen.
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.
•Backlit display is easy to read
•Displays ambient (measured) temperature at all times
•One-touch access to setpoint temperature
•Preset program settings
•Temporary and permanent override of schedule
•Early start ensures the right temperature at the right time
•Built-in compressor protection

11
Thermostat controls
M32700
Heat Off Cool Auto On
Fan
Set: Press to set
time/day/schedule.
Hold: Press
to override
programmed
temperature
control.
Run: Press to
resume program
schedule.
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.
•Heat: Heating system control.
•Off: All systems off.
•Cool: Cooling system control.
Display screen
M32701
We
Lo
Batt
Wake
Set
am
Heat
75
On
6:30
Low battery warning
(see page 16)
Setpoint indicator
Appears when the setpoint
temperature is displayed.
Temperature
The ambient (measured)
temperature is normally displayed.
To view the setpoint temperature,
press the Up or Down button
once. The setpoint temperature will
appear for five seconds.
System status
Cool on: Cooling system is on.
Heat on: Heating system is on.
When Cool On is flashing, compressor
protection is engaged (see page 15).
Current day/time
(see page 12)
Current program period
Wake/Leave/Return/Sleep
(see pages 12–14)

12
Set Time
am
6:30
M32702
Set Day
We
M32703
Set the time and day
1. Press the SET button, then press
sor tto set the clock time.
2. Press the SET button, then press
sor tto select the day of the
week.
3. Press RUN to save & exit.
NOTE: If the clock flashes, the
thermostat will follow your settings
for the Monday “Wake” time period
until you reset the time and day.
Program Schedule
You can program four time periods each day, with different settings for
weekdays and weekends. We recommend the pre-set settings (shown in the
table below), since they can reduce your heating/cooling expenses.
Wake - Set to the time you
awaken and the temperature you
want during the morning, until
you leave for the day.
Leave - Set to the time you leave
home and the temperature you
want while you are away (usually
an energy-saving level).
Return - Set to the time you
return home and the temperature
you want during the evening,
until bedtime.
Sleep - Set to the time you go to bed and the temperature you want overnight
(usually an energy-saving level).
NOTE: Leave and Return periods can be canceled on weekends.
Heat Cool
Wake
(6:00 am) 70 °78 °
Leave
(8:00 am) 62 °85 °
Return
(6:00 pm) 70 °78 °
Sleep
(10:00 pm) 62 °82 °

13
To adjust program schedules (RTHL2510)
To adjust program schedules (RTHL2410)
1. Press SET until Set Schedule is
displayed.
2. Press sor tto set your weekday
Wake time (Mo-Fr), then press SET.
3. Press sor tto set the
temperature for this time period,
then press SET.
4. Set time and temperature for the
next time period (Leave). Repeat
steps 2 and 3 for each weekday
time period.
5. Press SET to set weekend time
periods (Sa & Su), then press RUN
to save & exit.
NOTE: Make sure the thermostat is set
to the system you want to program
(Heat or Cool).
1. Press SET until Set Schedule is
displayed.
2. Press s or t to set your Wake
time for the day displayed, then
press SET.
3. Press s or t to set the
temperature for this time period,
then press SET.
4. Set time and temperature for the next time
period (Leave). Repeat steps 2 and 3 for
each day’s time period.
5. Press RUN to save & exit.
NOTE: Make sure the thermostat is set to the
system you want to program (Heat or Cool).
Mo
Wake
Set Schedule
Set
am
75
6:30
M32704
Mo Tu We Th Fr
Wake
Set Schedule
Set
am
75
6:30
M32706

14
Temporary
Wake
Set
am
70
6:30
M32708
Set
am
75
6:30
M32709
Program schedule override (temporary)
Press sor tto immediately adjust
the temperature. This will temporarily
override the temperature setting for
the current time period.
“Temporary” will appear on the display
and the current program period will
flash.
The new temperature will be
maintained only until the next
programmed time period begins (see
page 12).
To cancel the temporary setting at any
time, press RUN.
NOTE: Make sure the thermostat is set
to the system you want to control (heat
or cool).
Hold
Set
am
70
6:30
M32710
Set
am
75
6:30
M32709
Program schedule override (permanent)
Press HOLD to permanently adjust
the temperature. This will override
the temperature settings for all time
periods.
The “Hold” feature turns off the
program schedule and allows you to
adjust the thermostat manually, as
needed.
Whatever temperature you set will
be maintained 24 hours a day, until
you manually change it, or press RUN
to cancel “Hold” and resume the
program schedule.
NOTE: Make sure the thermostat is
set to the system you want to control
(heat or cool).

15
Program schedule override (permanent)
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 if you have a heat pump). When
the safe wait time has elapsed, the
message stops flashing and the
compressor turns on.
We
Wake
am
Cool
75
On
6:30
M32711
Early Start
This feature allows the heating or
cooling to turn on before the program
start time, so the temperature is
reached at the time you set. For
example: Set the Wake time to 6 am,
and the temperature to 70°. The heat
will come on before 6 am, so the
temperature is 70° by the time you
wake at 6. The next time period is
displayed when the system is activated
before a scheduled time period.
We
Wake
am
Cool
75
On
6:30
M32712

16
Battery replacement
Install two fresh AAA batteries when
Lo Batt flashes on the screen. Lo
Batt appears for 60 days before the
batteries are depleted.
Replace batteries once a year, or
when you will be away for more than a
month.
Most settings are stored in non-volatile
(permanent) memory. Only the clock
and the day must be set after you
replace the batteries.
Pull at bottom to remove
thermostat from wallplate.
Turn thermostat over,
insert fresh AAA
alkaline batteries, then
reinstall thermostat.
Set the System switch to Off before removing
the batteries. Otherwise, the heating/cooling
system could remain activated even when
batteries are removed.
RTHXXXX
M32707
W/
Aux
Not
Used
Heat Off Cool Auto On
Fan
M32705

17
Troubleshooting
If you have difficulty with your thermostat, please try the following suggestions.
Most problems can be corrected quickly and easily.
Display is
blank
•Check circuit breaker and reset if necessary.
•Make sure power switch at heating & cooling system is on.
•Make sure furnace door is closed securely.
•Make sure fresh AAA alkaline batteries are correctly
installed.
Heating
or cooling
system does
not respond
•Set system switch to Heat. Make sure the temperature is
set higher than the Inside temperature.
•Set system switch to Cool. Make sure the temperature is
set lower than the Inside temperature.
•Wait 5 minutes for the system to respond.
Temperature
settings do
not change
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).
“Cool On” or
“Heat On” is
flashing
•Compressor protection feature is engaged. Wait 5 minutes
for the system to restart safely, without damage to the
compressor.
“Heat On” is
not displayed
•Set the System switch to Heat, and set the temperature
level above the current room temperature.
“Cool On” is
not displayed
•Set the System switch to Cool, and set the temperature
level below the current room temperature.

Operating
Manual
RTHL2510/RTHL2410 Series
Programmable Thermostat

Read and save these instructions.
® U.S. Registered Trademark. Patents pending.
Copyright © 2013 Honeywell International Inc. All rights reserved.
This manual covers the following models:
RTHL2510
RTHL2410
CAUTION: EQUIPMENT DAMAGE HAZARD.
To prevent possible compressor damage, do not operate cooling system when outdoor
temperature is below 50°F (10°C).

RTHL2510/RTHL2410
About your new thermostat
Thermostat features
Thermostat is preset, ready to go
Quick reference to controls
Quick reference to display
Programming & Operation
Set time and day
Select system setting
Select fan setting
Using program schedules
Adjust program schedule (RTHL2510)
Adjust program schedule (RTHL2410)
Program schedule overrides
Compressor protection
Early Start
Appendices
Battery replacement
Customer assistance
In case of difficulty
This thermostat is ready to go!
Your new thermostat is pre-programmed
and ready to go.
See page 10 to check settings.
Table of contents
RTHL2510/RTHL2410