Honeywell RTH7400 series User manual

Quick Start Guide
Programmable Thermostat
RTH7400/RTH7500, RET97 Series

2
Installation is Easy
Label wires and remove your old thermostat
Install and wire your new thermostat
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
We are here to help.
Call 1-800-468-1502 for
wiring assistance before
returning the thermostat
to the store.
This thermostat works on 24 volt or 750 mV systems.
It will NOT work on 120/240 Volt systems.

3
50 60 70 80 F
OFF
AUTOEM. HEAT
EM. HEATAUX. HEAT
50 60 70 80
MCR33835A
Remove old thermostat but leave wallplate with
wires attached.
2Remove Old Thermostat
1Turn OFF Power to Heating/
Cooling System
Is there a sealed tube containing
mercury? If so, see back cover
for proper disposal instructions.
Leave wallplate
in place
Old thermostat
Cover
or

4
MCR33763
Label the wires using the supplied wire labels as you
disconnect them, then remove the old wallplate.
3Label Wires with Tags
Wire Labels
Wire color might not match labels.
M31545
NOTE: Jumper wire used on old thermostat? If yes, note
what letters the jumper connected and review in wiring
section.

5
Remove wallplate from the new thermostat.
M28073
4Separate Wallplate from
New Thermostat
Wallplate

6
Mount the new wallplate using the included screws
and anchors.
5Mount Wallplate
MCR28094
Drill 3/16-in. holes for drywall
Drill 7/32-in. holes for plaster

7
Simply match wire labels.
Remove metal jumper if you have both Rand Rc wires.
MCR28070
W2
Y2
C
G
Y
W
RC
R
LABELED WIRES
SCREW
CONVENTIONAL
INSERT WIRES
THEN TIGHTEN SCREWS
WIRE HOLE
Y
G
R
W
CONVENTIONAL
6Connect Wires
Labels don’t match? See Wiring Notes (over).
Have a Heat Pump system? See Wiring Notes (over).
Call 1-800-468-1502 for wiring assistance.

8
Install two AA alkaline batteries and remove tab.
MCR28101
Back of thermostat
Remove tab.
7Install Batteries
MCR28102

9
M28103
Install thermostat onto the wallplate on the wall.
Turn the power back on to the heating/cooling system.
8Install Thermostat onto Wallplate
9Turn Power Back ON
or

10
MCR33842
Go Back Next Done
6
15
2012
10 Set Time and Date
Press sor tto set month, then press NEXT.
Press sor tto set day, then press NEXT.
Press sor tto set year, then press DONE.
Press sor tto set time, then press DONE to save
and exit.
Month Year Day
MCR33843
Done
10:10