Summary of the content on the page No. 1
®
CT87A,B,J Round Thermostat
LOW VOLTAGE (15 TO 30 VAC),
THERMOSTAT AND MOUNTING HARDWARE
Installation Instructions
Verify that you have the
1
correct thermostat
Using the compatibility chart
below, verify that you purchased
the correct CT87Thermostat for
your heating/cooling system. If
you are unsure which model is
right for your system, visit
www.honeywell.com/
yourhome or call Honeywell
Customer Care at
1-800-468-1502.
Compatible with:
Heating/Cooling system CT87A CT87B CT87J
Heating
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CT87A,B,J ROUND® THERMOSTAT Prepare for installation 2 1. Carefully unpack your new thermostat; rough handling may affect its accuracy. Save your receipt and identify the following parts: CT87 Thermostat 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
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CT87A,B,J ROUND® THERMOSTAT 5. Label the wires using the wiring Fig. 2. Labeling wires. labels that came with the CT87. Identify each wire using the letter of the terminal on the old thermo- stat (Fig. 2). Do not label the wires by color. 6. Disconnect the wires from the old thermostat and wrap them around a pencil to keep them from falling back into the wall (Fig. 3). M19086 Fig. 3. Wrapping wires. WIRES THROUGH WALL OPENING MERCURY NOTICE If this thermostat is replacing a control that
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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. Rotate the wallplate/subbase until the wiring openings are aligned and the two screw holes on the left and right side of the wallplate/subbase align with the screw holes on the cover ring. You will be inserting screws thro
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CT87A,B,J ROUND® THERMOSTAT 1. Place the cover ring against the outlet box so that the arrow in the middle of the cover ring is pointing up. 2. Pull the wires through the wiring hole on the bottom left side of the cover ring. 3. Align the screw slots on the cover ring with the outlet box screw holes, and attach the cover ring to the outlet box with two 1/2-in. screws. 4. Place the wallplate or subbase over the cover ring so that the wiring holes line up, and pull the wires through. 5. Loose
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CT87A,B,J ROUND® THERMOSTAT Wire the thermostat 6 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. Wiring Cross-reference Connect to Connect to Connect to Wire Label CT87A CT87B CT87J R, RH, 4, V R RH R Rc, R Rc W, W , H W W W 1 Y, Y , M Y Y Y 1 G, F GG B See Fig. 9 B* O O* See Fig. 13 P *Never attach wires to both the B and O terminals. 2. Strip the wire
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O T U A • N O N A F CT87A,B,J ROUND® THERMOSTAT Fig. 8. CT87A for a 2-wire heating only system. CT87A WALLPLATE POWER R TO Y SYSTEM W HEAT M20183 Fig. 9. CT87A for a 3-wire hot water heating only system. CT87A WALLPLATE WIRE LABELS (LETTERS ON ORIGINAL THERMOSTAT TERMINALS) R R 3-WIRE W HOT WATER Y ZONE VALVE W B M20184 Fig. 10. CT87B for a 4-wire heating/cooling system. CT87B SUBBASE POWER TO FAN SYSTEM RH G COOL RC Y W HEAT JUMPER RH TO RC M20185 7 69-0274-6 T A E H • F F O • L O O C
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O O O T T T U U U A A A • • • N N N O O O N N N A A A F F F CT87A,B,J ROUND® THERMOSTAT Fig. 11. CT87B for a 5-wire heating/cooling system. CT87B SUBBASE HEATING POWER TO FAN SYSTEM RH G COOLING TO RC POWER SYSTEM Y W COOL HEAT M20225 Fig. 12. CT87J for a 4-wire single stage heat pump. CT87J SUBBASE HEAT TO FAN SYSTEM WG POWER Y P COOL R O REVERSING VALVE B HEAT REVERSING VALVE DO NOT ATTACH WIRES TO BOTH B AND O JUMPER W TO Y M20186 Fig. 13. CT87J for 4-wire single stage heat pump. CT87J SUBBAS
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1.2 .6 .5 .4 .3 .2 CT87A,B,J ROUND® THERMOSTAT Mount the thermostat 7 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. IMPORTANT: This prevents the thermostat from being damaged. Fig. 14. Adjusting heat anticipator indicator. HEAT ANTICIPATOR INDICATOR HOLE SUITABLE FOR .15 .12 .10 PENCIL POINT TO MOVE INDICATOR SCALE
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CT87A,B,J ROUND® THERMOSTAT Set the heat anticipator for your system 8 IMPORTANT: Setting the heat anticipator allows the thermostat to maintain accurate temperature control. 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. Your heating system: Heat anticipator setting: Steam 1.2 Hot water heat
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CT87A,B,J ROUND® THERMOSTAT Check cooling IMPORTANT: To avoid damaging the compressor in the air conditioner, do not operate the cooling system when the outdoor temperature is below 50°F (10°C). 1. If your CT87 has a subbase, set the System switch on the left to Cool. IMPORTANT: After heating is tested, wait five minutes before switch- ing to Cool on the CT87J model. 2. Lower the temperature setting below room temperature. The cooling system should start. 3. Raise the temperature setting a
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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. If, at any time during the warranty period, the product is defective or malfunctions, Honeywell shall repair or replace it (at Honeywells option) within a reasonable period of time. If the product is defective, (i) return it, with
