Honeywell RTH7400 series User manual

Owner’s Manual
Read and save these
instructions.
For help please visit
yourhome.honeywell.com
RTH7400/RTH7500
RET97D Series
Programmable
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
• This thermostat works with virtually all System Types
• It is preset for the most common 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.

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.
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
NE PAS JETER
LE MERCURE
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.
This thermostat contains a Lithium battery which may contain
Perchlorate material.
Perchlorate Material—special handling may apply, See www.dtsc.
ca.gov/hazardouswaste/perchlorate
M28103
® U.S. Registered Trademark. Patents pending.
US Patent No. 6,595,430; 7,114,554; 7,274,972; 7,225,054 and other patents pending

3
Installation
Installation............................................3
Advanced Installation.........................10
About your new thermostat
Controls and Home screen
quick reference...................................13
Preset energy-saving schedules........14
Programming and operation
Setting the clock.................................14
Adjusting program schedules.............15
Overriding schedules temporarily ......16
Overriding schedules permanently ....16
Auto Changeover ...............................17
Change filter.......................................17
Replace batteries ...............................18
Appendices
Troubleshooting..................................19
Limited warranty.................................20
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.
Wallplate
M28073

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 here
(see notes, below).
We are here to help. Call 1-800-468-1502 for wiring assistance.
M28094
Remove metal jumper if you have
both Rand Rc wires.
MCR28845
W2
Y2
C
G
Y
W
RC
R
LABELED WIRES
SCREW
CONVENTIONAL
INSERT WIRES
THEN TIGHTEN SCREWS
WIRE HOLE
Y
G
R
W
CONVENTIONAL

6
Alternate Wiring (Conventional Systems)
If labels do not match terminals, connect wires as shown here (see notes,
below).
Alternate Wiring (Heat Pump)
If labels do not match letters on thermostat, see page 7.
Remove metal jumper connecting Rand Rc only if you must connect both
Rand Rc wires.
If your old thermostat had both Rand RH wires, remove metal jumper.
Connect the Rwire to the Rc terminal, and the RH wire to the Rterminal.
If your old thermostat had only 1 Cor C1 wire, connect it to the Cterminal.
If your old thermostat had 2 Cor C1 wires, wrap each separately with
electrical tape and do not connect them.
C
G
Y
W
RC
R
W2
Y2 Y2
W2
W
Y
G
MCR32160
R
2
Rc
2
C
3
NOTE: If Eand Aux
do not each have a
wire connected, use a
small piece of wire to
connect them to each
other.
C
G
Y
O/B
RC
R
HEAT PUMP
MCR28104A
Aux
E
L
LABELED WIRES
SCREW
INSERT WIRES
THEN TIGHTEN SCREWS
WIRE HOLE
Y
G
R
O
HEAT PUMP
Aux

7
Alternate Wiring (For Heat Pumps Only)
2
3
5
3 5
46
6
MCR32161
C
G
Y
O/B
RC
R
AUX
E
L
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, attach the Bwire to
the Cterminal. If another wire is attached to the Cterminal, stop now and
contact a qualified contractor for help.
If your old thermostat had Y1, W1 and W2 wires, stop now and contact a
qualified contractor for help.
If Lterminal is used, Cterminal wire must be connected (contact a
contractor if there is no Cwire).
If Eand Aux terminals do not each have a wire connected, use a small
piece of wire to connect them to each other.
5
6

8
7 Install Batteries
Install two AA alkaline batteries and remove tab.
M31544
or
Circuit breaker box Heating/cooling system
power switch
M28101
Back of thermostat
Remove tab
M28102
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.
M28103

9
10 Set Time and Date
1. Press sor tto set month, then press NEXT.
2. Press sor tto set day, then press NEXT.
3. Press sor tto set year, then press DONE.
4. Press sor tto set time, then press DONE to save and exit.
11 If your system type is...
If your system type is:
qSingle Stage Heat and Cool
Congratulations, you’re done!
If your system type is:
qMultistage Heat and Cool
qHeat Pump* without Backup Heat
qHeat Pump* with Backup Heat
qHeat Only
qCool Only
Continue with Advanced Installation on next page 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.
If you are not sure of your system type or if you have other
questions, call us toll-free at 1-800-468-1502.
This thermostat works on 24 volt or 750 mV systems. It will NOT work on
120/240 volt systems.
Go Back Next Done
6
15
2006
M28095
Done
10:10
M28096

10
Advanced Installation
Enter System Setup
1. Press and release the left button.
2. Press and hold the center button until the screen changes (approximately
5 seconds).
System & Fan Schedule Clock & More
M27459
System Fa
nD
one
20
0120
M28069
Changing Settings
1. Press the sor tbutton to
change the setting.
2. Press NEXT to advance to next
function.
3. Press DONE to save & exit. Go Back Next Done
20
0120
Function Setting
NOTE: Some functions in the following pages may not appear due to previous
selections made.
Function Description Setting
Press the sor tbutton to change the setting.
0120 Year Setting
(first two digits)
20 = Year 20xx
21 = Year 21xx
0130 Year Setting
(second two digits)
01 - 99 (i.e., 2001 - 2099
0140 Month Setting 01 - 12 (i.e., January - December)
0150 Date Setting 01 - 31

11
Function Description Setting
Press the sor tbutton to change the setting.
0170 Select System Type 1Heat/cool: Gas, oil or electric heating with central air
conditioning.
2Heat pump: Heat pump without backup or auxiliary heat.
3Heat only: Gas, oil or electric heat without central air
conditioning.
4Heat only with fan: Gas, oil or electric heat without central air
conditioning.
5Hot water heat only (no fan): Gas, oil or hot water heat
without central air conditioning.
6Cool only: Central air conditioning only.
7Heat pump: Heat pump with backup or auxiliary heating.
8Heat/Cool Multiple stages: 2 heat stages (wires on W and
W2), 2 cooling stages (wires on Y and Y2).
9Heat/Cool Multiple stages: 2 heat stages (wires on W and
W2), 1 cooling stage (wire on Y).
10Heat/Cool Multiple stages: 1 heat stage (wire on W), 2
cooling stages (wires on Y and Y2).
0180 Heating Fan Control 0Gas or oil heat: Use this setting if you have a gas or oil
heating system (system controls fan operation).
1Electric heat: Use this setting if you have an electric heating
system (thermostat controls fan operation).
0190 Heat Pump Changeover Valve
(for heat pumps only)
0Cooling changeover valve: Use this setting if you connected
a wire labeled “O” to the O/B terminal (see page 6).
1Heating changeover valve: Use this setting if you connected
a wire labeled “B” to the O/B terminal (see page 7).
0240 Heating Cycle Rate 5Gas or oil furnace: Standard gas/oil furnace (less than 90%
efficiency).
9Electric furnace: Electric heating systems.
3Heat pump, hot water or high-efficiency furnace: Hot water
system or gas furnace (more than 90% efficiency).
1Gas/oil steam or gravity system: Steam or gravity heat
systems.
0270 Emergency Heat Cycle Rate
(heat pumps only)
9Electric furnace: Electric heating systems.
0300 Manual/Auto Changeover 0Manual changeover (Heat/Cool/Off).
1Automatic changeover (Heat/Cool/Auto/Off). Automatically
turns on Heat or Cool based on room temperature. Note:
System maintains minimum 3°F difference between heat and
cool settings.
0320 Temperature Format (°F/°C) 0Fahrenheit
1Celsius
0330 Daylight Saving Time On/Off 0Off: No adjustment for daylight saving time.
1On: Auto-change to daylight saving time (for areas that do
not use the new 2007 DST calendar).
2On: Auto-change to daylight saving time (2007 and beyond,
for areas that use the new 2007 DST calendar).

12
Function Description Setting
Press the sor tbutton to change the setting.
0500 Furnace Filter Change Reminder 0Off (no reminder)
1Reminder in about 1 month
2Reminder in about 3 months
3Reminder in about 6 months
4Reminder in about 9 months
5Reminder in about 1 year
6Reminder in about 3 years
0530 Smart Response® Technology 1On
0Off
0600 Maximum Heat Setting 90°F (other options: 40-89°F [4-32°C])
0610 Minimum Cool Setting 50°F (other options: 51-99°F [11-37°C])
0640 Clock Format 1212-hour clock (i.e., “3:30 pm”)
2424-hour clock (i.e., “15:30”)
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.
• Easy-to-follow menu programming.
• One-touch temp control overrides program schedule at any time.
• Precise comfort control keeps temperature within 1°F of the level you set.
• Change/check reminder lets you know when to replace furnace filter.
• Large display with backlight is easy to read—even in the dark

13
M28426
Arrow buttons
Press the up or down buttons to
adjust temperature or to make
selections from screen menus.
System & Fan
Press to select fan
operation or system.
Schedule
Press to set program schedule (see
pages 14–16).
Clock & More
Press to set clock or furnace filter
reminder.
Thermostat controls
System & Fan Schedule Clock & Mode
System
Cool Fan Auto
Mon
Set to
Heat OnRecovery
AM
75
75
6:01
M28078A
Display screen
Day of week
Press the SYSTEM & FAN button, then press…
…SYSTEM to select:
Heat: Heating system control.
Cool: Cooling system control.
Auto: Thermostat automatically selects heating or
cooling depending on the indoor temperature.
Off: All systems off.
Em Heat: Emergency & Auxiliary Heat control.
Compressor is locked out. (Select models only.)
System Status
Cool On: Cooling system
is on.
Heat On: Heating system
is on.
Aux Heat On: Auxiliary
heating system is activated
(heat pump systems only)
Temperature settingCurrent timeCurrent inside
temperature
Smart
Response®
Technology
in effect (see
page 18)
…FAN to select:
Auto: Fan runs only when heating
or cooling system is on.
On: Fan runs continuously.
Press DONE to exit and save
settings.

14
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 °75 °
Leave
(8:00 am) 62 °83 °
Return
(6:00 pm) 70 °75 °
Sleep
(10:00 pm) 62 °78 °
Clock setting
1. To set the current time display,
press CLOCK & MORE, then press s
or tto adjust the time.
Press and hold s or tto advance
the time more quickly.
2. Press DONE to save & exit (or press
GO BACK to exit without changing
the time).
NOTE: The real-time clock should
never require adjustment since it
automatically updates for daylight
savings time, and stores all date/time
information.
System & Fan Schedule Clock & More
MCR28079
Go Back Done
Mon
AM
6:01
MCR28080

15
To adjust program schedules (RTH7400 only)
1. Press SCHEDULE, then EDIT to see
weekdays.
2. Press SELECT DAY to highlight Mon-Fri
(they will share the same settings).
3. Press NEXT STEP twice, then press sor
tto set Wake time for selected days.
4. Press NEXT STEP, then sor tto set Heat
temperature for this time period.
5. Press NEXT STEP, then sor tto set Cool
temperature for this time period.
6. Repeat steps 3-5 to program other time
periods (LEAVE, RETURN, SLEEP), then
press DONE.
7. Repeat steps 1-6 to program Saturday/
Sunday. (Press sor tuntil the desired
day is flashing, then press SELECT DAY.)
8. Press DONE to save & exit.
System & Fan Schedule Clock & More
MCR28084
Go Back Edit View
MCR28085
Go Back Next Step Done
Period
Wake
MON
TUE
WED
THU
FRI
Set to
Heat
AM
62
6:00
MCR28086
To adjust program schedules (RTH7500/RET97D only)
1. Press SCHEDULE, then EDIT to see
weekdays.
2. Press SELECT DAY. You can select
multiple days to program with the same
settings.
3. Press NEXT STEP twice, then press sor
tto set Wake time for selected day(s).
4. Press NEXT STEP, then sor tto set
Heat temperature for this time period.
5. Press NEXT STEP, then sor tto set
Cool temperature for this time period.
6. Repeat steps 3-5 to program other time
periods (LEAVE, RETURN, SLEEP), then
press DONE.
7. Repeat steps 1-6 to program any
remaining days. (Press sor tuntil
the desired day is flashing, then press
SELECT DAY.)
8. Press DONE to save & exit.
System & Fan Schedule Clock & More
MCR28084
Go Back Edit View
MCR28085
Go Back Next Step Done
Period
Wake
MON
TUE
WED
THU
FRI
Set to
Heat
AM
62
6:00
MCR28086

16
Program schedule override (temporary)
Press sor tto immediately adjust
the temperature. This will temporarily
override the temperature setting for
the current time period.
The new temperature will be
maintained until the next time period.
When the timer expires, the program
schedule will resume and set the
temperature to the level you’ve
programmed for the current time
period.
To cancel the temporary setting at
any time, press USE SCHEDULE.
System & FanUse
Schedule Clock & More
System
Heat Fan Auto
MonTemporary
Set to
Heat On
AM
62
68
6:08
MCR28087
Program schedule override (permanent)
Press sor tto adjust temperature,
then press HOLD. This will turn off the
program schedule.
Whatever temperature you set will
be maintained 24 hours a day, until
you manually change it, or press
USE SCHEDULE to cancel “Hold” and
resume the program schedule. Hold Cancel
System
Heat Fan Auto Permanent Hold
Mon
Set to
AM
62
68
6:08
MCR28088

17
CAUTION: To avoid possible compressor damage, do not use Auto
Changeover if the outside temperature drops below 50°F (10°C).
Auto changeover
Use this feature in climates where both air conditioning and heating are
used on the same day. When the system mode is in Auto, the thermostat
automatically selects heating or cooling depending on the indoor temperature.
While in the Auto mode, if a schedule override takes place (temporarily or
permanently) the thermostat will automatically adjust the cooling and heating
settings to maintain a 3-degree separation between the cool and heat settings.
For example, if the heat temperature is
raised to where it gets within 3-degrees
of the cool setting, the display will show
an up arrow next to “Cool” to show the
thermostat is raising the cool setting up
to maintain a 3-degree separation.
The display will also show both “Auto”
and either “Heat” or “Cool” for which
temperature setting you are currently
adjusting. Press the system button to
select between the heat and cool to
view/adjust either mode.
69
System
Hold
Heat
Cool
Fan Auto
Cancel
Set To
Tue
PM
74
1:09
Temporary
MCR27486
System Auto
Heat
If activated during installation, the
furnace filter reminder alerts you
when it is time to replace your
filter.
Press RESET after changing the
filter, to restart the timer.
To reset the reminder interval
before it expires:
1. Press MORE, then NEXT.
2. Press RESET.
3. Press DONE to save and exit.
Reset Schedule Clock & More
System
Heat Fan Auto
Set to
Change Filter
Heat On
AM
70
70
6:01
MCR2808
9
Filter reminder
Reset Next Done
Days
60
MCR28090

18
Special features
Smart Response®Technology: This feature allows the thermostat to
“learn” how long the furnace and air conditioner take to reach programmed
temperature settings, 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 message “Recovery” is displayed when the system is activated before a
scheduled time period.
Compressor Protection: This feature forces the compressor to wait a few
minutes before restarting, to prevent equipment damage. During the wait time,
the message “Wait” is displayed on screen.
Auto Changeover: This feature is used in climates where both air conditioning
and heating are used on the same day. When the system is set to Auto,
the thermostat automatically selects heating or cooling depending on the
indoor temperature. Heat and cool settings must be at least 3 degrees apart.
The thermostat will automatically adjust settings to maintain this 3-degree
separation.
Turn thermostat over, insert
fresh AA alkaline batteries,
then reinstall thermostat.
Battery replacement
MCR28101
Batteries are optional (to provide
backup power) if your thermostat
was wired to run on AC power when
installed.
Install fresh batteries immediately when
the LO BATT warning begins flashing.
The warning flashes about 30 days
before batteries are depleted.
Even if the warning does not appear,
you should replace batteries once a
year, or before leaving home for more
than a month.
Grasp thermostat and pull to
remove from wallplate
M28103

19
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 AA alkaline batteries are correctly installed.
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).
Heating or
cooling system
does not respond
• Press SYSTEM to set system to Heat. Make sure the temperature
is set higher than the Inside temperature.
• Press SYSTEM to set system to Cool. Make sure the temperature
is set lower than the Inside temperature.
• Check circuit breaker and reset if necessary.
• Make sure power switch at heating & cooling system is on.
• Make sure furnace door is closed securely.
• Wait 5 minutes for the system to respond.
Cannot change
system setting
to Cool
• Check Function 0170: System Type to make sure it is set to
match your heating and cooling equipment.
Fan does not
turn on when
heat is required
• Check Function 0180: Heating Fan Control to make sure it is set
to match your heating equipment.
Heating system
is running in cool
mode
• Check Function 0170: System Type to make sure it is set to
match your heating and cooling equipment.
Red light is on • If thermostat is in Emergency Heat mode the red light is normal.
It shows that the thermostat is in emergency heat mode.
• If thermostat is not in Emergency Heat mode, contact a qualified
service contractor for repair.
“Wait” appears
on the screen • Compressor protection feature is engaged. Wait 5 minutes for the system to restart safely, without damage to the compressor.
Heat pump
issues cool air
in heat mode, or
warm air in cool
mode
• Check Function 0190: Heat Pump Changeover Valve to make
sure it is properly configured for your system.
For assistance with this product, please visit http://yourhome.honeywell.com or
call Honeywell Customer Care toll-free at 1-800-468-1502.
Special features

Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN 55422
yourhome.honeywell.com
® U.S. Registered Trademark.
© 2015 Honeywell International Inc.
33-00090EF—01 M.S. 07-15
Printed in U.S.A.
33-00090EF-01
1-year limited warranty
Honeywell warrants this product, excluding battery, to be free from defects in the
workmanship or materials, under normal use and service, for a period of one (1) year
from the date of purchase by the consumer. If at any time during the warranty period the
product is determined to be defective or malfunctions, Honeywell shall repair or replace it
(at Honeywell’s option).
If the product is defective,
(i) return it, with a bill of sale or other dated proof of purchase, to the place from which
you purchased it; or
(ii) call Honeywell Customer Care at 1-800-468-1502. Customer Care will make the
determination whether the product should be returned to the following address:
Honeywell Return Goods, Dock 4 MN10-3860, 1885 Douglas Dr. N., Golden Valley, MN
55422, or whether a replacement product can be sent to you.
This warranty does not cover removal or reinstallation costs. This warranty shall not apply
if it is shown by Honeywell that the defect or malfunction was caused by damage which
occurred while the product was in the possession of a consumer.
Honeywell’s sole responsibility shall be to repair or replace the product within the terms
stated above. HONEYWELL SHALL NOT BE LIABLE FOR ANY LOSS OR DAMAGE
OF ANY KIND, INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES
RESULTING, DIRECTLY OR INDIRECTLY, FROM ANY BREACH OF ANY WARRANTY,
EXPRESS OR IMPLIED, OR ANY OTHER FAILURE OF THIS PRODUCT. Some states
do not allow the exclusion or limitation of incidental or consequential damages, so this
limitation may not apply to you.
THIS WARRANTY IS THE ONLY EXPRESS WARRANTY HONEYWELL MAKES ON
THIS PRODUCT. THE DURATION OF ANY IMPLIED WARRANTIES, INCLUDING THE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, IS
HEREBY LIMITED TO THE ONE-YEAR DURATION OF THIS WARRANTY.
Some states do not allow limitations on how long an implied warranty lasts, so the above
limitation may not apply to you. This warranty gives you specific legal rights, and you may
have other rights which vary from state to state.
If you have any questions concerning this warranty, please write Honeywell Customer
Relations, 1985 Douglas Dr, Golden Valley, MN 55422 or call 1-800-468-1502.