Installation Instructions
Page 1
... backup heat. CT87A,B,J Round® Thermostat LOW VOLTAGE (15 TO 30 VAC), THERMOSTAT AND MOUNTING HARDWARE 1 Verify that you have the correct thermostat Using the compatibility chart below, verify that you are unsure which model is compatible with 2-wire cooling-only systems. ® U.S. No No * CT87A is right for your system, visit www.honeywell.com/ yourhome or call Honeywell Customer...
... backup heat. CT87A,B,J Round® Thermostat LOW VOLTAGE (15 TO 30 VAC), THERMOSTAT AND MOUNTING HARDWARE 1 Verify that you have the correct thermostat Using the compatibility chart below, verify that you are unsure which model is compatible with 2-wire cooling-only systems. ® U.S. No No * CT87A is right for your system, visit www.honeywell.com/ yourhome or call Honeywell Customer...
Installation Instructions
Page 2
.... Save your heating system. drill bit • Wire cutter/stripper or sharp knife • Pencil 3 Remove the old thermostat 1. OLD THERMOSTAT ANTICIPATOR SCALE Current setting: If you cannot find the heat LEVER anticipator setting on the old thermostat, you reach Step 8 of M20206 this installation. 4. CT87A,B,J ROUND® THERMOSTAT 2 Prepare for your type of MERCURY SWITCH IN A THERMOSTAT system when you can...
.... Save your heating system. drill bit • Wire cutter/stripper or sharp knife • Pencil 3 Remove the old thermostat 1. OLD THERMOSTAT ANTICIPATOR SCALE Current setting: If you cannot find the heat LEVER anticipator setting on the old thermostat, you reach Step 8 of M20206 this installation. 4. CT87A,B,J ROUND® THERMOSTAT 2 Prepare for your type of MERCURY SWITCH IN A THERMOSTAT system when you can...
Installation Instructions
Page 3
...subbase If installing on the wall (wallplate shown). Identify each wire using the wiring labels that contains mercury in a sealed tube, do not place your M20133 local ...on the old thermo- M19086 MERCURY NOTICE Fig. 3. Do not label the wires by color. 6. Wrapping wires. Label the wires using the letter of this thermostat is replacing a control that came...RING WALLPLATE NO. 4 X 1 INCH SHEET METAL SCREWS (2) 3 THERMOSTAT WIRING OPENING M20188 69-0274-6 Disconnect the wires from the old thermostat and wrap them from falling back into the wall (Fig. 3). Fig...
...subbase If installing on the wall (wallplate shown). Identify each wire using the wiring labels that contains mercury in a sealed tube, do not place your M20133 local ...on the old thermo- M19086 MERCURY NOTICE Fig. 3. Do not label the wires by color. 6. Wrapping wires. Label the wires using the letter of this thermostat is replacing a control that came...RING WALLPLATE NO. 4 X 1 INCH SHEET METAL SCREWS (2) 3 THERMOSTAT WIRING OPENING M20188 69-0274-6 Disconnect the wires from the old thermostat and wrap them from falling back into the wall (Fig. 3). Fig...
Installation Instructions
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...to the wall: Position so that the UP indicator on the wallplate is pointing up. 2. If installing on the cover ring. ROUND HEAD SCREW (2) A THERMOSTAT WIRING HOLE 1 THE TWO INNER HOLES ARE USED WITH WALLPLATE. 2 IF OUTLET BOX IS HORIZONTAL, MOUNT COVER RING IN POSITION SHOWN,... as you marked. 5. CT87A,B,J ROUND® THERMOSTAT 1. BINDING HEAD SCREW (2) OUTLET BOX 1 2 COVER RING SUBBASE 1/4 IN. Position the wallplate or subbase. • If using the cover ring: Position the cover ring against the wall so that the fan and heating/cooling switches are aligned and the two...
...to the wall: Position so that the UP indicator on the wallplate is pointing up. 2. If installing on the cover ring. ROUND HEAD SCREW (2) A THERMOSTAT WIRING HOLE 1 THE TWO INNER HOLES ARE USED WITH WALLPLATE. 2 IF OUTLET BOX IS HORIZONTAL, MOUNT COVER RING IN POSITION SHOWN,... as you marked. 5. CT87A,B,J ROUND® THERMOSTAT 1. BINDING HEAD SCREW (2) OUTLET BOX 1 2 COVER RING SUBBASE 1/4 IN. Position the wallplate or subbase. • If using the cover ring: Position the cover ring against the wall so that the fan and heating/cooling switches are aligned and the two...
Installation Instructions
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...cover ring is level. 5 69-0274-6 To level the subbase, use the leveling posts directly below the Heat and Fan indicators. SPIRIT LEVEL LEVELING POSTS (2) OPENING FOR THERMOSTAT WIRING MOUNTING SLOTS M3319A 2. screws. 4. Place the wallplate or subbase over the cover ring so that the ...wallplate or subbase is pointing up , and pull the wires through the wiring hole on the left side of the cover ring. 3. CT87A,B,J ROUND® THERMOSTAT 1. Loosely attach the wallplate/subbase to maintain accu- Tighten the mounting screws after making ...
...cover ring is level. 5 69-0274-6 To level the subbase, use the leveling posts directly below the Heat and Fan indicators. SPIRIT LEVEL LEVELING POSTS (2) OPENING FOR THERMOSTAT WIRING MOUNTING SLOTS M3319A 2. screws. 4. Place the wallplate or subbase over the cover ring so that the ...wallplate or subbase is pointing up , and pull the wires through the wiring hole on the left side of the cover ring. 3. CT87A,B,J ROUND® THERMOSTAT 1. Loosely attach the wallplate/subbase to maintain accu- Tighten the mounting screws after making ...
Installation Instructions
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..., R W, W1, H Y, Y1, M G, F B O See Fig. 13 Connect to CT87A R W Y See Fig. 9 Connect to Connect to CT87B CT87J RH R Rc W W Y Y G G B* O* P *Never attach wires to fit the wires underneath the terminal screws (Fig. 7). CT87A,B,J ROUND® THERMOSTAT 6 Wire the thermostat 1. Use the wiring cross-reference table below to match each wire beneath its corresponding terminal on the CT87 wallplate or subbase.
..., R W, W1, H Y, Y1, M G, F B O See Fig. 13 Connect to CT87A R W Y See Fig. 9 Connect to Connect to CT87B CT87J RH R Rc W W Y Y G G B* O* P *Never attach wires to fit the wires underneath the terminal screws (Fig. 7). CT87A,B,J ROUND® THERMOSTAT 6 Wire the thermostat 1. Use the wiring cross-reference table below to match each wire beneath its corresponding terminal on the CT87 wallplate or subbase.
Installation Instructions
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CT87B for a 2-wire heating only system. COOL • OFF • HEAT FAN ON RH G RC Y W AUTO • CT87B SUBBASE POWER FAN COOL TO SYSTEM HEAT JUMPER RH TO RC M20185 7 69-0274-6 CT87A WALLPLATE R Y W POWER HEAT TO SYSTEM M20183 Fig. 9. CT87A for a 4-wire heating/cooling system. CT87A for a 3-wire hot water heating only system. R Y W CT87A WALLPLATE WIRE LABELS (LETTERS ON ORIGINAL THERMOSTAT TERMINALS) R 3-WIRE W HOT WATER ZONE VALVE B M20184 Fig. 10. CT87A,B,J ROUND® THERMOSTAT Fig. 8.
CT87B for a 2-wire heating only system. COOL • OFF • HEAT FAN ON RH G RC Y W AUTO • CT87B SUBBASE POWER FAN COOL TO SYSTEM HEAT JUMPER RH TO RC M20185 7 69-0274-6 CT87A WALLPLATE R Y W POWER HEAT TO SYSTEM M20183 Fig. 9. CT87A for a 4-wire heating/cooling system. CT87A for a 3-wire hot water heating only system. R Y W CT87A WALLPLATE WIRE LABELS (LETTERS ON ORIGINAL THERMOSTAT TERMINALS) R 3-WIRE W HOT WATER ZONE VALVE B M20184 Fig. 10. CT87A,B,J ROUND® THERMOSTAT Fig. 8.
Installation Instructions
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... • POWER WG 1Y P R B O HEAT REVERSING VALVE COOL REVERSING VALVE TO SYSTEM HEAT PUMP COMPRESSOR DO NOT ATTACH WIRES TO BOTH B AND O 1 IF WIRES ARE ATTACHED TO Y OR W, AND P ON YOUR OLD THERMOSTAT, CONTACT YOUR LOCAL CONTRACTOR FOR FURTHER ASSISTANCE. CT87J for a 5-wire heating/cooling system. CT87B for 4-wire single stage heat pump. CT87J for a 4-wire single stage heat pump. M20225 COOL •...
... • POWER WG 1Y P R B O HEAT REVERSING VALVE COOL REVERSING VALVE TO SYSTEM HEAT PUMP COMPRESSOR DO NOT ATTACH WIRES TO BOTH B AND O 1 IF WIRES ARE ATTACHED TO Y OR W, AND P ON YOUR OLD THERMOSTAT, CONTACT YOUR LOCAL CONTRACTOR FOR FURTHER ASSISTANCE. CT87J for a 5-wire heating/cooling system. CT87B for 4-wire single stage heat pump. CT87J for a 4-wire single stage heat pump. M20225 COOL •...