Installation Guide

RTH8500
Touchscreen Programmable Thermostat

69-1902EF-1

This thermostat provides control of 24 VAC heating and cooling systems, or 750mV heating systems.
MERCURY NOTICE: Do not place your old thermostat in the trash if it contains mercury in a sealed tube. Contact your local waste management authority for instructions regarding recycling and proper disposal.
This thermostat contains a Lithium battery which may contain Perchlorate material. Perchlorate Materialspecial handling may apply, See www.dtsc.ca.gov/hazardouswaste/perchlorate

Need Help?

For assistance with this product please visit http://yourhome.honeywell.com or call Honeywell Customer Care toll-free at 1-800-468-1502
Read and save these instructions.
U.S. Registered Trademark. US Patent No. 6595430, D520,386 and other patents pending. Copyright 2007 Honeywell International Inc. All rights reserved.

Table of contents

Getting started
Installation tips.. 2. Pre-installation checklist.. 3

System setup

How to change settings.. 16 System settings..17-23

Old thermostat removal

Remove old thermostat.. 5 Identify and label wires.. 6.

Appendices

In case of difficulty.. 24 Customer assistance.. 27 Limited warranty.. 28
New thermostat installation
Wallplate mounting.. 7 Wire connections.. 10 Battery installation. 13 Thermostat mounting. 14 Time/date settings. 15
Installation is easyeven if youve never done it before!
Your new thermostat has been designed for fast, easy installation. Just follow the simple, step-by-step instructions in the following pages.
Install in three simple steps
Label wires and remove your old thermostat (see pages 5-6). Install and wire your new thermostat (see pages 7-15). Set your new thermostat to match your heating/cooling system (see pages 16-23).

Installation tips

Have everything you need ready to go before you begin (see pages 3-4). Do not use wire color as a guide. Use wire labels instead (see page 6).
TURN OFF POWER at heating/cooling system (or fuse/circuit-breaker panel) before you begin installation.
Pre-installation checklist
Check to make sure your package includes the following items:
RTH8500 thermostat (wallplate attached to back)

Operating manual

Wall anchors and mounting screws (2 each)

Wire labels

Required tools & supplies
No. 2 Phillips screwdriver Small pocket screwdriver Drill Drill bit (3/16 for drywall, 7/32 for plaster) Hammer Pencil Electrical tape Level (optional) Three fresh AAA alkaline batteries
Remove your old thermostat
1. Turn off power at heating/cooling system (or fuse/circuit-breaker panel). 2. Remove cover and thermostat, but leave wallplate with wires attached.
Leave wallplate in place Is there a sealed tube containing mercury? If so, see inside front cover of this manual for proper disposal instructions.

Old thermostat Cover

Label wires and remove old wallplate
Use a screwdriver to disconnect wires one by one. As you disconnect each wire, wrap it with the label matching the letter on your old thermostat. (Adhesive labels are supplied in your thermostat package.) Remove the old wallplate only after all wires are labeled. Be careful not to let loose wires fall into the wall opening.
Wrap supplied labels securely around each wire. Do not let wires fall into wall opening!
IGNORE WIRE COLORS: Use only letter designations to identify wire types.

Remove wallplate

Grasp top and bottom of wallplate and pull to remove from thermostat.

Wallplate

Mark wallplate mounting position
1. Pull wires through wallplate. 2. Level wallplate if desired. 3. Mark positions of both screw holes.

Mount wallplate

1. Drill holes at pencil-marked locations: 3/16 holes for drywall 7/32 holes for plaster.

2. Use hammer to tap anchors into holes until flush with wall.
3. Place wallplate over anchors and insert screws. Check level if desired, then tighten screws.
Connect wires (typical installation)
Remove metal jumper if you have both R and Rc wires. 1. Match each labeled wire with same letter on terminal. (Use HEAT PUMP letters if you have a heat pump system.)
2. Use a screwdriver to loosen screw terminals, insert wires, then tighten screws. 3. Push any excess wire back into the wall opening.

Labels dont match?

If labels do not match letters on thermostat, see pages 11-12. Insert wires, then tighten screws.
Alternate wiring (conventional systems)
If labels do not match terminals, connect wires as shown here (see notes, below). 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.

RC R W Y G C Y2 W2

Rc R W Y G C Y2 W2
Alternate wiring (for heat pumps only)
If labels do not match letters on the thermostat, check the chart at right and connect to terminal as shown here (see notes, below). Leave metal jumper in place, connecting R & Rc terminals. If your old thermostat had both V and VR wires, stop now and contact a qualified contractor for help. 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. If your old thermostat had Y1, W1 and W2 wires, stop now and contact a qualified contractor for help. If L terminal is used, C terminal wire must be connected (contact a contractor if there is 5 no C wire). If E and Aux terminals do not each have a wire connected, use a small piece of wire to 6 connect them to each other. 12

Install batteries

Install 3 fresh AAA alkaline batteries in back of thermostat.

Back of thermostat

Remove tab and mount thermostat

Remove tab.

Align pins on back of thermostat with slots in wallplate, then push gently until thermostat snaps into place.
TIP: If wires interfere when you try to mount the thermostat, push excess wire back into the wall opening.
Set time/date and restore electrical power
Press s/t to set date Press s/t to set month Press s/t to set year

DONE TUE

Press s/t to set time

1:00 PM

Press DONE to save and exit
Press DONE to save changes
TIP: Dont forget to restore electrical power at the heating/cooling system, or at the fuse/circuit-breaker panel.

FAN AUTO

1. Press SYSTEM.

Inside

Set To

Outside

2. Press and hold blank center key until the display changes.

SYSTEM

CANCEL

Following Schedule

SCREEN
3. Change settings as required (see pages 17-23).

AUTO Function

Setting
Press s/t to change setting
4. Press DONE to exit & save changes.
Press s/t to select function NOTE: Because of choices you make while programming, some functions in the following pages may not appear. 16
Year setting (first two digits)
Function 0120 Options: Press s/t to change the first two digits of the year: 20 = Year 20xx 21 = Year 21xx Press s/t to change the last two digits of the year: 01 - 99 (i.e., 2001 - 2099) Press s/t to change the current month: 01 - 12 (i.e., January - December) Press s/t to change the current date: 01 - 31 17
Year setting (second two digits)
Function 0130 Options: Function 0140 Options: Function 0150 Options:

Month setting

Date setting

Select system type

Function 0170 Options: Press s/t to select your system type: Heat/cool: Gas, oil or electric heating with central air conditioning. Heat pump: Single-stage heat pump (no backup or auxiliary heat). Heat only: Gas, oil or electric heat without central air conditioning. Heat only with fan: Gas, oil or electric heat without central air conditioning. Hot water heat (no fan): Gas, oil or hot water heat without central air conditioning. 6 Cool only: Central air conditioning only. 7 Multi-stage heat pump: Heat pump with backup or auxiliary heating. 8 Conventional multi-stage system: 2 heat stages (wires on W and W2), 2 cooling stages (wires on Y and Y2). 9 Conventional multi-stage system: 2 heat stages (wires on W and W2), 1 cooling stage (wire on Y). 10 Conventional multi-stage system: 1 heat stage (wire on W), 2 cooling stages (wires on Y and Y2). 5

Heating fan control

Function 0180 Options: Press s/t to select your heating system & fan control: 0 Gas or oil heat: Use this setting if you have a gas or oil heating system (system controls fan operation). 1 Electric heat: Use this setting if you have an electric heating system (thermostat controls fan operation). Press s/t to select whether your changeover valve is used in heating or cooling: 0 Cooling changeover valve: Use this setting if you connected a wire labeled O to the O/B terminal (see page 11). 1 Heating changeover valve: Use this setting if you connected a wire labeled B to the O/B terminal (see page 11).
Heat pump changeover valve (for heat pumps only)

Function 0190 Options:

Heating cycle rate
Function 0240 Options: Press s/t to select your heating system: 5 Gas or oil furnace: Use this setting if you have a standard gas or oil furnace that is less than 90% efficient. 9 Electric furnace: Use this setting if you have an electric heating system. 3 Hot water or high-efficiency furnace: Use this setting if you have a hot water system or a gas furnace of greater than 90% efficiency. 1 Gas/oil steam or gravity system: Use this setting if you have a steam or gravity heat system. Press s/t to select your heating system: 9 Electric furnace: Electric heating systems. 5 Gas or oil furnace: Standard gas/oil furnace (less than 90% efficiency). 3 Hot water or high-efficiency furnace: Hot water system or gas furnace (more than 90% efficiency). 1 Gas/oil steam or gravity system: Steam or gravity heat systems.
Emergency heat cycle rate (heat pumps only)

Function 0270 Options:

Manual/Auto changeover
Function 0300 Options: Press s/t to select manual or automatic changeover: 0 Manual changeover (Heat/Cool/Off). 1 Automatic changeover (Heat/Cool/Auto/Off). Note: System maintains minimum 3F difference between heat and cool settings. CAUTION: To avoid possible compressor damage, set to option 0 if the outside temperature drops below 50F (10C).

Temperature format (F/C)

Function 0320 Options: Press s/t to set the temperature display format: 0 Fahrenheit 1 Celsius Press s/t to select an option: 0 Off: No adjustment for daylight savings time. 1 On: Auto-change to daylight savings time (through 2006, and for areas that do not use the new 2007 DST calendar). 2 On: Auto-change to daylight savings time (2007 and beyond, for areas that use the new 2007 DST calendar). 21
Daylight savings time on/off

Function 0330 Options:

Furnace filter change reminder
Function 0500 Options: This feature displays an alert to remind you to change the furnace filter. Press s/t to set the desired reminder interval: 6 Off (no reminder to change furnace filter) Reminder after 10-day run time (about 1 month) Reminder after 30-day run time (about 3 months) Reminder after 60-day run time (about 6 months) Reminder after 90-day run time (about 9 months) Reminder after 120-day run time (about 1 year) Reminder after 365-day run time (about 3 years) Note: Press RESET to cancel the alert.
Smart Response Technology (on/off)

Function 0530 Options:

Press s/t to turn this feature on or off (see Operating Manual for more information): 1 On 0 Off Press s/t to set the clock display format: 12 12-hour clock (i.e., 3:30 pm) 24 24-hour clock (i.e., 15:30)

Clock format

Function 0640 Options:

In case of difficulty

If you have difficulty with your thermostat, please try the following suggestions. Most problems can be corrected quickly and easily.
Display is blank Cannot change system setting to Cool Fan does not turn on when heat is required Make sure fresh AAA alkaline batteries are properly installed (see page 13). Check Function 0170: System Type to make sure it is set to match your heating and cooling equipment (see page 18).
Check Function 0180: Heating Fan Control to make sure it is set to match your heating equipment (see page 19).
Wait appears on the screen
Compressor protection feature is engaged. Wait 5 minutes for the system to restart safely, without damage to the compressor.
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. 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.

Red warning light is on

Heat pump issues cool air in heat mode, or warm air in cool mode Heating and cooling equipment running at the same time (or heat does not turn off) Heating system is running in cool mode Check Function 0190: Heat Pump Changeover Valve to make sure it is properly configured for your system (see page 19).
Check Function 0170: System Type to make sure it is set to match your heating and cooling equipment (see page 18). Grasp and pull thermostat away from wallplate. Check to make sure bare wires are not touching each other. Check Function 0170: System Type to make sure it is set to match your heating and cooling equipment (see page 18).

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.

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 Honeywells 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.
Honeywells 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. In Canada, write Retail Products ON15-02H, Honeywell Limited/ Honeywell Limite, 35 Dynamic Drive, Toronto, Ontario M1V4Z9.