120-240 volts Multistage: A conventional system with more than one stage, or an outdoor heating/cooling unit (compressor) with auxiliary or backup heat. * CT87A is compatible with 2-wire cooling-only systems. ® U.S. Registered Trademark Copyright © 2002 Honeywell All Rights Reserved ®...
• Screws: two 1-in. sheet metal screws, two 1/2-in. binding head screws, and two 1/4-in. round head screws • Wallplate (CT87A) or subbase (CT87B, CT87J) • Cover ring (select models only). Necessary if installing on an outlet box. Optional if installing directly on the wall; can be used to hide wall marks.
Install the cover ring and wallplate or subbase If installing on the wall Refer to Fig. 4 as you work. Fig. 4. Installing wallplate/subbase on the wall (wallplate shown). CT87A,B,J ROUND® THERMOSTAT COVER RING WALLPLATE NO. 4 X 1 INCH SHEET METAL SCREWS (2) Fig.
CT87A,B,J ROUND® THERMOSTAT 1. If using the cover ring: Position the cover ring against the wall so that the arrow in the middle of the cover ring is pointing up. 2. Position the wallplate or subbase. • If using cover ring: Place the wallplate/subbase over the cover ring.
To level the subbase, use the leveling posts directly below the Heat and Fan indicators. Fig. 6. Leveling the wallplate. 2. Tighten the mounting screws after making sure that the wallplate or subbase is level. CT87A,B,J ROUND® THERMOSTAT SPIRIT LEVEL OPENING FOR THERMOSTAT...
CT87A,B,J ROUND® THERMOSTAT Wire the thermostat 1. Use the wiring cross-reference table below to match each old thermostat wire with its corresponding terminal on the CT87 wallplate or subbase. See Fig. 8 through 13 wiring diagrams. Wire Label R, RH, 4, V...
Fig. 8. CT87A for a 2-wire heating only system. Fig. 9. CT87A for a 3-wire hot water heating only system Fig. 10. CT87B for a 4-wire heating/cooling system JUMPER R TO R CT87A,B,J ROUND® THERMOSTAT CT87A WALLPLATE POWER HEAT CT87A WALLPLATE...
CT87A,B,J ROUND® THERMOSTAT Fig. 11. CT87B for a 5-wire heating/cooling system. Fig. 12. CT87J for a 4-wire single stage heat pump. Fig. 13. CT87J for 4-wire single stage heat pump. 69-0274-6 JUMPER W TO Y IF WIRES ARE ATTACHED TO Y OR W, AND P ON YOUR OLD THERMOSTAT, CONTACT YOUR LOCAL CONTRACTOR FOR FURTHER ASSISTANCE.
Mount the thermostat 1. Pull off the thermostat cover and discard the red plastic insert that holds the mercury switch in place during shipping. 2. Using a pencil point, slide the heat anticipator indicator to 1.2 on the scale as shown in Fig. 14.
1. Using a pencil point, move the heat anticipator pointer to the number that you recorded in Step 3, sub-step 3. If you could not find the anticipator setting on the old thermostat, use the setting for your type of system shown in the table below.
Switch Setting System Cool Heat Auto CT87A,B,J ROUND® THERMOSTAT Result The thermostat controls your cooling system. Both the heating and cooling systems are off. The thermostat controls your heating system. The fan runs continuously. The fan runs only with the heating or cooling system.
CT87A,B,J ROUND® THERMOSTAT 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.