RTH7400D Programmable Thermostat OWNER’S GUIDE The RTH7400D Thermostat provides electronic control of 24 Vac heating and cooling systems or 750 mV heating systems. For assistance with your Honeywell product, please visit www.honeywell.com/yourhome or call Honeywell Customer Care toll free at 1-800-468-1502. Read and Save these Instructions Patents Pending ® U.S. Registered Trademark © 2004 Honeywell International Inc.
Contents Prepare for Installation ............................................................ 3 Follow Important Instructions .................................................. 5 Remove Old Thermostat ......................................................... 6 Follow Special Instructions...................................................... 7 Label Old Thermostat Wires ................................................... 10 Mount New Wallplate to Wall ..................................................
Step 1. Prepare for Installation 1. Check that the following items are included: WALLPLATE THERMOSTAT MOUNTING SCREWS (2) AND WALL ANCHORS (2) OWNER'S GUIDE WIRE LABELS CAUTION CARD OWNER'S GUIDE CAUTION TURN OFF POWER to system at the furnace, or at the fuse/circuit breaker panel before you begin. Match the letter of your old thermostat wire with the terminal of the corresponding letter on your new thermostat or base.
Step 1. Prepare for Installation (Cont) 2. Check that you have everything required for the installation: • Two AA alkaline batteries • No. 2 Phillips screwdriver and standard pocket screwdriver • Drill • Drill bit—use 3/16 in. for drywall; use 7/32 in.
Step 2. Follow Important Instructions 1. Do not connect the wires to the new thermostat based on wire color because damage can occur to the heating and/or cooling system. These Installation Instructions explain later how to use the enclosed wire labels to correctly mark the wires connected to your old thermostat. OLD THERMOSTAT YELLOW WHITE W Y RED G GREEN ! DO NOT WIRE NEW THERMOSTAT BASED ON WIRE COLOR.
Step 3. Remove Old Thermostat 1. 2. 3. Turn off power at the heating and/or cooling system or fuse/circuit breaker panel. Remove the cover from the old thermostat. Remove the old thermostat from the wall or wallplate. Do not remove the wires. OLD THERMOSTAT WALLPLATE W Y THERMOSTAT G COVER R C L .18 .2 .9 .7 .5 O .25 N G E R .4 .3 M22036 MERCURY NOTICE If you are replacing a thermostat that contains mercury in a sealed tube, do not place your old thermostat in the trash.
Step 4. Follow Special Instructions 1. 2. 3. If you have two C and/or C1 wires connected to your old thermostat, do not connect them to your new thermostat. Disconnect the C and/or C1 wires. Make sure they do not touch each other or any other wires. Wrap the bare end of each C and/or C1 wire with electrical tape.
Step 4. Follow Special Instructions (Cont) 4. If you have only one C and/or C1 wire connected to your old thermostat, connect this wire to C on the new thermostat.
Step 4. Follow Special Instructions (Cont) 5. If you find any wires not connected to your old thermostat, do not connect them to your new thermostat. Wrap the end of the wires that are not connected with electrical tape. 6.
Step 5. Label Old Thermostat Wires 1. 2. As you disconnect each wire, use the enclosed wire labels to wrap a wire label around each wire that matches the letter designation. Do not allow the wires to fall into the wall opening after the wires are disconnected. Remove any remaining part of the old thermostat from the wall.
Step 6. Mount New Wallplate to Wall 1. Separate the wallplate from the thermostat as shown.
Step 6. Mount New Wallplate to Wall (Cont) 2. Pass the labeled wires through the wire hole on the wallplate.
Step 6. Mount New Wallplate to Wall (Cont) 3. Position the wallplate on the wall with the arrow pointing up. Level the wallplate (for appearance only) and mark the two mounting holes with a pencil.
Step 6. Mount New Wallplate to Wall (Cont) 4. 5. Move the wallplate aside and drill holes at the locations marked on the wall. Drill 3/16 in. holes for drywall or 7/32 in. holes for plaster. Tap the wall anchors into the drilled holes until even with the wall surface. DRILLED HOLES (2) WALL ANCHORS (2) WALLPLATE MOUNTING SCREWS (2) M22293 6. 7. Position the wallplate over the wall anchors. Insert the mounting screws into the wall anchors. Check leveling, if desired, and tighten the mounting screws.
Step 7. Connect Wires to New Wallplate 1. 2. Match the labeled wires to the letter designations on the wallplate. Select the correct letter designations to follow for your system. If you have a standard heating and/or cooling system, use the CONVENTIONAL letter designations. If you have a heat pump system, use the HEAT PUMP letter designations to wire the new thermostat. M22294 See table on page 30 to help you determine if you have a CONVENTIONAL or HEAT PUMP system.
Step 7. Connect Wires to New Wallplate (Cont) 3. 4. If wires are to be connected to both Rc and R, loosen the Rc and R screw terminals and remove the metal jumper wire. If only one of the terminals, Rc or R, is to be connected, leave the metal jumper wire in place.
Step 7. Connect Wires to New Wallplate (Cont) 5. 6. Loosen the screw terminals. Insert the labeled wires into the holes on the side of the terminal block that match the letter designations. Tighten the screw terminals. If any of the labeled wires do not match the letter designations, see next page for wire connections.
Step 7. Connect Wires to New Wallplate (Cont) 7. Compare letter designations on your old and new thermostats. Use the information below if you are wiring a CONVENTIONAL System. Use the information on page 20 if you are wiring a Heat Pump system.
Step 7. Connect Wires to New Wallplate (Cont) NOTES FOR CONVENTIONAL HEATING AND COOLING SYSTEMS 1 If wires will be connected to both RC and R on the new thermostat, remove metal jumper wire between RC and R. Leave metal jumper wire in place if only one of the terminals, RC or R, will be connected on the new thermostat. 2 If wires were connected to both R and RH terminals on the old thermostat, remove metal jumper wire between RC and R on the new thermostat.
Step 7. Connect Wires to New Wallplate (Cont) 8. Compare letter designations on your old and new thermostats. Use the information below if you are wiring a HEAT PUMP system. Possible letter designations on the labeled wires HEAT PUMP letter designations on the new thermostat 1 RC 2 VR or V or R R 3 H or B, O O/B Y1 or M or Y Y F or G G 3 X or B, C C F or L L X2 or X, E E 4 AUX, W1, W or W2 AUX M22210 Be sure to read the note referenced in the numbered triangles above.
Step 7. Connect Wires to New Wallplate (Cont) NOTES FOR HEAT PUMP SYSTEMS 1 Leave metal jumper wire between RC and R in place. 2 If the old thermostat had separate wires on both the V and VR, some system modification is required. Call your local heating and cooling contractor for assistance. 3 If the old thermostat had wires on both O and B, be sure to attach the B wire to the C letter designation on the new thermostat. If another wire is already matched to the C, contact Honeywell.
Step 7. Connect Wires to New Wallplate (Cont) 9. Push excess wire back into the wall opening. Keep wires in the shaded area.
Step 8. Install Batteries 1. Install two fresh AA alkaline batteries on the back of the thermostat as marked on the thermostat. BATTERIES (2) BATTERY HOLDER BACK OF THERMOSTAT 2. M22259 Remove tab labeled “Remove during installation” in the lower right corner of the thermostat back.
Step 9. Attach New Thermostat to Wallplate 1. Align the screw blocks with the pins on the back of the thermostat. WALLPLATE TERMINAL SCREW BLOCK PINS ON BACK OF THERMOSTAT 2. 3. M22299 Push the thermostat straight onto the wallplate until it snaps into place. Turn on the power at the heating and/or cooling system or fuse/circuit breaker panel. If the wires interfere with mounting the thermostat to the wallplate, push the excess wire back into the wall opening.
Step 10. Set the Calendar This thermostat is designed to automatically keep current time and day in memory for up to ten years, under normal use, once the calendar is set. When the thermostat is first powered, the display is ready to set the calendar. 1. Use Up or Down arrow button to set the Month.
Step 10. Set the Calendar (Cont) 6. 7. Press the Done button to advance to the Time. Use the Up or Down arrow button to set the Time. UP AND DOWN BUTTONS CHANGES TIME PM Clock More Done DONE BUTTON ADVANCES TO HOME SCREEN 8. Press the Done button.
Step 11. Configure Installer Setup 1. 2. Use the Installer Setup Menu to match your new thermostat to your heating and/or cooling system. Follow the steps in this section to set up your thermostat. Press and release the System button.
Step 11. Configure Installer Setup (Cont) 3. Press and hold the center button for approximately five seconds, until the screen changes. System Auto Fan Auto Em Heat Off Cool FanUseEdit System & Fan CancelDone M22305 4. Release the center button when the display on your thermostat matches the display below.
11. Configure Installer Setup (Cont) 5. 6. 7. Press the Up or Down arrows to select your setting for Installer Setup Number 0120 below. After you select your setting, press the Next button to go to the next Installer Setup Number. Follow steps 5 and 6 to set Installer Setup Numbers 0130, 0140 and 0150 to complete setting the calendar.
Step 11. Configure Installer Setup (Cont) 8. 9. Press the Up or Down arrows to select your setting for Installer Setup Number 0170. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 10. 11. 12. If you do not have a number 0180 on the left side of your display, go to the next page. If you have a number 0180 on the left side of your display, press the Up or Down arrow to select your setting for Installer Setup Number 0180. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 13. 14. 15. If you do not have a number 0190 on the left side of your display, go to the next page. If you have a number 0190 on the left side of your display, press the Up or Down arrow to select your setting for Installer Setup Number 0190. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 16. 17. 18. If you do not have a number 0240 on the left side of your display, go to the next page. If you have a number 0240 on the left side of your display, press the Up or Down arrow to select your setting for Installer Setup Number 0240. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 19. 20. Press the Up or Down arrow to select your setting for Installer Setup Number 0320. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 21. 22. Press the Up or Down arrow to select your setting for Installer Setup Number 0330. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 23. 24. Press the Up or Down arrow to select your setting for Installer Setup Number 0500. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 25. 26. Press the Up or Down arrow to select your setting for Installer Setup Number 0530. After you select your setting, press the Next button to go to the next Installer Setup Number.
Step 11. Configure Installer Setup (Cont) 27. 28. 29. Press the Up or Down arrow to select your setting for Installer Setup Number 0640. After you select your setting, press the Done key to exit the Installer Setup and save your settings. Congratulations! The installation of the thermostat is complete.
Get to Know Your Thermostat Buttons Thermostat DOWN BUTTON LOWERS TEMPERATURE SETTING OR MAKES SELECTIONS IN OTHER SCREENS UP ARROW BUTTON RAISES TEMPERATURE SETTING OR MAKES SELECTIONS IN OTHER SCREENS PM System System & Fan Fan Schedule Clock & More SCHEDULE BUTTON SELECTS PROGRAMMING MODE SYSTEM & FAN BUTTON CLOCK & MORE BUTTON SELECTS FAN AUTO OR ON SELECTS HEAT, OFF, COOL AND EM HEAT SELECTS TIME AND FURNACE FILTER INFORMATION M22316 39 69-1726—1
Get to Know Your Thermostat Display Display TEMPERATURE SETTING SHOWS CURRENT DAY OF WEEK CURRENT TIME Mon Aux System Schedule he INDICATES THERMOSTAT IS "CALLING FOR COOL OR HEAT" CURRENT SYSTEM SETTING CURRENT FAN SETTING 69-1726—1 Clock & More M M22317 40
Set System Setting Set System Setting Press the System button to select Heat, Off or Cool: Heat—Thermostat controls the heating system. Off—Heating and cooling systems are both off. Cool—Thermostat controls the cooling system. Em. Heat (Heat Pump Systems with Auxiliary Heat)—Thermostat controls emergency heat and auxiliary heat, if needed. Heat Pump compressor is not operational. CAUTION Equipment Damage Hazard. Air conditioning compressor damage possible.
Set System Setting (Cont) Set Fan Setting 1. Press System & Fan button. 2. Press the Fan button to select Auto or On: Auto—Normal setting for most homes.The fan runs only when the heating or cooling system is on. On—The fan runs continuously. Use this setting for improved air circulation or for more efficient air cleaning.
Program Your Heating and Cooling Schedule Your thermostat can control up to four different schedule periods Monday through Friday and Saturday and/or Sunday : Wake—Period when you awaken and want your home at a comfortable temperature. Leave—Period when you are away from home and want an energy-saving temperature. Return—Period when you return home and want your home back to a comfortable temperature. Sleep—Period when you are asleep and want an energysaving temperature. Edit Schedule 1.
Program Your Heating and Cooling Schedule (Cont) 2. Press the Edit button.
Program Your Heating and Cooling Schedule (Cont) 3. Monday through Friday flashes. Press the Select Day button to select Monday through Friday. The days selected are scheduled with the same times and temperatures. Checkmarks appear next to the days selected. Mon Tue Wed Thu Fri Sat Sun Select Day Next Step Cancel M22332 You can select Mon-Fri as a block of days and select Saturday and Sunday separately. Use the Up and Down buttons to move up and down the list of days.
Program Your Heating and Cooling Schedule (Cont) 4. Press the Next Step button. Once pressed, Wake flashes to show it is selected.
Program Your Heating and Cooling Schedule (Cont) 12. When complete, press the Done button. “Saved” appears on the display to indicate changes are being saved to the day(s) selected. Mon Tue Wed Thu Fri Sat Saved M22334 13. To set a program schedule for Saturday and Sunday, repeat steps 1 through 12. To select Saturday and/or Sunday to schedule, use the Down arrow button until Sat or Sun is flashing. When the desired day(s) is flashing, press the Select Day button.
Set Time Set Time 1. 2. Press Clock & More button. Use the Up and Down arrow buttons to set the current time. Tue PM Done Go Back M22335 3. Press the Done button. The current day of the week should already be set correctly. If not, see Step 11, Configure Installer Setup.
Set Temperature Overrides Hold Temperature Until (Temporary Hold) Hold temperature temporarily until the next scheduled period time. 1. Press the Up or Down arrow buttons next to the temperature you want to adjust. “Temporary” appears on the display above the set temperature. MOVES TEMPERATURE SETTING UP OR DOWN M22336 2. Press the Use Schedule button to cancel “Temporary” temperature and resume schedule.
Set Temperature Overrides (Cont) Permanent Hold Permanent Hold changes the temperature setting until Permanent Hold is cancelled. 1. 2. Use the Up or Down arrow buttons to set the temperature you want during the hold. Press the Hold button. “Permanent Hold” shows on the display. Tue PM System System & Fan Fan Use Schedule Clock & More M22337 3. Press the Use Schedule button to cancel “Permanent Hold” and resume the schedule. The display shows Permanent Hold until it is cancelled.
Use Your Filter Timer The Filter Timer notifies you when to change your furnace filter. Reset Filter Timer 1. 2. “Change Filter” appears on the display when the filter timer expires. Press the Reset button to restart the filter timer. Tue PM System Heat Fan Schedule Clock & More Reset M22338 See Step 11 to turn the Filter Timer Change Reminder feature on or off.
Use Your Filter Timer (Cont) View or Reset The Remaining Change Filter Time 1. 2. Press the Clock & More button. Press the Next button. Change Filter Days Reset Next Done M22339 3. 4. Press the Reset button to Restart the filter timer, if desired. Press the Done button. See Step 11 to turn the Filter Timer Change Reminder feature on or off.
Understand Temperature Recovery Feature Your thermostat comes with a feature called Adaptive Intelligent Recovery™, which eliminates all guesswork when setting your schedule. How long does it take the furnace to warm your house in the morning before you get out of bed or how long does it take the air conditioner to cool your house in the afternoon before you return from work? No problem. The thermostat determines that for you.
Replace Batteries 1. When the LO Battery indicator is flashing, replace the batteries promptly with two fresh AA alkaline batteries. 2. Remove thermostat from the wallplate by pulling straight out.
Replace Batteries (Cont) 3. Remove the old batteries and insert two fresh AA alkaline batteries, as marked on the thermostat.
Replace Batteries (Cont) 4. Align the screw blocks with the pins on the back of the thermostat. WALLPLATE TERMINAL SCREW BLOCK PINS ON BACK OF THERMOSTAT M22299 5. Push the thermostat straight onto the wallplate until it snaps into place.
Review Battery Tips 1. Replace the batteries as soon as LO Batt flashes in the display. The LO Battery indicator flashes in the display one month before the batteries run down completely. 2. Always use fresh AA alkaline batteries. Non-alkaline batteries do not last as long and can leak, causing thermostat damage. 3. Although the thermostat has a Low Battery indicator, replace the batteries once a year to prevent the thermostat and heating/cooling system from shutting down due to lack of battery power.
Built-in Compressor Protection The RTH7400D Thermostat has built-in compressor protection (minimum-off timer) that prevents the compressor from restarting too early after a shutdown. The minimum-off timer is activated after the compressor turns off. If there is a call during the minimum-off timer, the thermostat shows “Wait” in the display.
Troubleshooting Tips If . . . Then . . . Display is blank. Temperature settings do not change. Heating system does not turn on. Check that fresh AA alkaline batteries are installed as marked on the thermostat. Check that the temperature settings are: • Heating 40°F to 90°F(4.5°C to 32°C). • Cooling 50°F to 99°F (10°C to 37°C). • Set the system to Heat by pressing the System button.
Troubleshooting Tips (Continued) If . . . Then . . . Cannot set Check Installer Setup Number 0170, System setting Heating and/or Cooling System Type; make to Cool. sure the setting matches the installed heating and/or cooling system. “Heat On” is Set the System setting to Heat and set the not shown in temperature setting above the room the display. temperature.
Troubleshooting Tips (Continued) If . . . Both the heating and cooling systems are running at the same time. Then . . . Check Installer Setup Number 0170, Heating and/or Cooling System Type, and make sure the setting matches the installed heating and/or cooling system. Check and make sure the bare portions of the wires are not touching. Heating system Check Installer Setup Number 0170, is running in Heating and/or Cooling System Type, and cool mode.
Customer Assistance For assistance with your Honeywell product, please visit www.honeywell.com/yourhome or call Honeywell Customer Care toll free at 1-800-468-1502.
Limited One-Year 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 defective or malfunctions, Honeywell shall repair or replace it (at Honeywell’s option) within a reasonable period of time.
Limited One-Year Warranty (Cont) 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.