Honeywell Home RTH7400 Programmable Thermostat Quick Start Guide

Honeywell Home RTH7400 Programmable Thermostat

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.

Turn Off Power to Heating/Cooling

Remove Old Thermostat

Remove old thermostat but leave wallplate with wires attached.

Label Wires with Tags

Label the wires using the supplied wire labels as you disconnect them, then remove the old wallplate.

NOTE: Jumper wire used on old thermostat? If yes, note what letters the jumper connected and review in wiring section.

Separate Wall Plate from new Thermostat

Remove wallplate from the new thermostat.

This thermostat contains a Lithium battery which may contain Perchlorate material.
Perchlorate Material—special handling may apply, See www.dtsc.ca.gov/hazardouswaste/perchlorate

MERCURY NOTICE:
Do not place your old thermostat in the trash if it contains mercury in a sealed tube. Contact the Thermostat Recycling Corporation at www.thermostat-recycle.org or 800-238-8192 for information on how and where to properly and safely dispose of your old thermostat.
CAUTION: To avoid possible compressor damage, do not run air conditioner if the outside temperature drops below 50°F (10°C).

Mount Wallplate

Mount the new wallplate using the included screws and anchors.

• Drill 3/16-in. holes for drywall
• Drill 7/32-in. holes for plaster

Connect 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.

Install Batteries

Install Thermostat onto Wallplate 
Install thermostat onto the wallplate on the wall.

Turn Power Back ON 
Turn the power back on to the heating/cooling system.

Set Time and Date

• Press to set month, then press NEXT.
• Pressto set day, then press NEXT.
• Pressto set year, then press DONE.
• Press to set time, then press DONE to save and exit.

If your system type is…

Single Stage Heat and Cool
Congratulations, you’re done!
Thermostat is set with energy saving schedule; see operating manual to adjust schedule.

If your system type is:

• Multistage Heat and Cool
• Heat Pump* without Backup Heat
• Heat Pump* with Backup Heat
• Heat Only
• Cool Only
  Continue to step 12a to match your thermostat to your sys-tem 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.

System Setup

Step 1
Press and release the left button.

Step 2
Press and hold the center button until the screen changes (approximately 5 seconds).

NOTE: Some functions may not appear due to thermostat model or previous selections made.

Step 3

1. Press to change setting.
2. Press NEXT to advance to next function. 3 Press DONE to save & exit.

Preferences (optional) 
Use the Setup and Navigation steps in 12a to set Display Preferences.

Wiring Notes

Conventional system

Alternate wiring (conventional systems)

• Remove metal jumper connecting R and Rc only if you must connect both R and Rc wires.
• If your old thermostat had both R and RH wires, remove metal jumper. Connect the R wire to the Rc terminal, and the RH wire to the R terminal.
• If your old thermostat had only 1 C or C1 wire, connect it to the C terminal. If your old thermostat had 2 C or C1 wires, wrap each separately with electrical tape and do not connect them.

Heat pump

Connect wires: Heat Pump

1. Match each labeled wire with same letter on new thermostat.
2. Use a screwdriver to loosen screws, insert wires into hole under screw, then tighten screws until wire is secure.
3. If E and Aux do not each have a wire connected, use a small piece of wire to connect them to each other.
4. Push any excess wire back into the wall opening.

Labels don’t match? If labels do not match letters on thermostat, see Alternate wiring (heat pump system only)

Alternate wiring (heat pump system only)

1. Leave metal jumper in place, connecting R & Rc terminals.
2. If your old thermostat had both V and VR wires, stop now and contact a qualified contractor for help.
3. If your old thermostat had separate O and B wires, attach the B wire to the C terminal. If another wire is attached to the C terminal, stop now and contact a qualified contractor for help.
4. If your old thermostat had Y1, W1 and W2 wires, stop now and contact a qualified contractor for help.
5. If L terminal is used, C terminal wire must be connected (contact a contractor if there is no C wire).
6. If E and Aux terminals do not each have a wire connected, use a small piece of wire to connect them to each other.

Customer assistance

For assistance with this product, please visit customer.resideo.com or call Customer Care toll-free at 1-800-468-1502.

Resideo Technologies, Inc.
1985 Douglas Drive North, Golden Valley, MN 55422 1-800-468-1502
69-2722—05 M.S. Rev. 07-21 | Printed in United States
© 2020 Resideo Technologies, Inc. All rights reserved.
This product is manufactured by Resideo Technologies, Inc. and its affiliates.
www.resideo.com

REFERENCE

Download Manual:

Honeywell Home RTH7400 Programmable Thermostat Quick Start Guide

Honeywell Home RTH7400 Programmable Thermostat Quick Start Guide