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
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.
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