Honeywell CT51A, CT53A User Manual

CT500 Electronic Thermostat

THERMOSTAT FOR APPEARANCE

OWNER'S GUIDE

MERCURY NOTICE

If this control is replacing a control that contains mercury in a sealed tube, do not place your old control in the trash. Dispose of it properly.

Contact your local waste management authority for instructions regarding recycling and the proper disposal of an old control. If you have questions, call Honeywell at 1-800-458-1502.

1 PREPARE FOR INSTALLATION

❑ Check Table 1 to be sure this thermostat is compatible

with your system. If not, return it to the retailer. For more information, call Honeywell at 1-800-468-1502.

❑ Acquire tool and items as needed. See Fig. 1.

Non-programmable Heat and/or Cool

Low Voltage (20 to 30 Vac) Thermostat and Wallplate

Congratulations on purchasing your new thermostat! More than 100 years of engineering expertise enabled this thermostat to provide you with a more comfortable and convenient living environment.

Direct any questions about this thermostat to the Honeywell Customer Relations Center at www.honeywell.com/yourhome or 1-800-468-1502, Monday - Friday, 7:00 am - 5:30 pm, Central time.

Model CT500

Fig. 1. Required installation tools and supplies.

CROSS-RECESSED SCREWDRIVER

WIRE CUTTER/STRIPPER OR SHARP KNIFE, IF NEEDED TO STRIP WIRES

LEVEL, IF NEEDED TO LEVEL

HAND OR POWER DRILL WITH 3/16 INCH DRILL BIT, IF NEEDED TO DRILL HOLES IN WALL

M18920

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CT500 ELECTRONIC THERMOSTAT

Table 1. System Compatibility

System Type Compatible with CT500

Gas — Standing Pilot

Gas — Electronic Ignition Yes

Gas-Fired Boilers

Gas — Millivolt No

Oil-Fired Boilers

Oil-Fired Furnace Yes

Electric Furnace No

Electric Air Conditioning Yes

Baseboard Electric (120/240 Line Volt) No

Heat Pumps/Multistage Equipment No

Not compatible with any 120/240 volt circuit. Not compatible with 2-wire White-Rodgers no. 1361 zone valves.

Not compatible with millivolt systems.

Compatible with 2-wire Honeywell zone valves. Isolating relay required for 3-wire thermostat zone valves.

Ye s

a,b

2 REMOVE OLD THERMOSTAT

❑ Test to be sure your heating and air conditioning

systems (where applicable) are working correctly. If either does not work, contact you local heating/air conditioning dealer. To avoid compressor damage, do not operate the cooling system when outdoor temperature is below 50°F (10°C).

CAUTION

Be careful when handling wires during installation. Damage to heating/cooling system possible.

Disconnect power at furnace or at main breaker/ fuse box before starting operation.

❑ Carefully unpack your new thermostat, wallplate, and

decorator cover plate; save package of screws, instructions and receipt.

❑ Remove the cover from the old thermostat. If it does

not snap off when pulled firmly from the bottom, check for a screw used to lock on the cover.

❑ Loosen screws holding the thermostat to the subbase,

wallplate and wall, and lift away.

❑ Disconnect wires from old thermostat or subbase. As

you disconnect each wire, use wire labels to identify the old terminal designation. If there are only two wires, they do not need labeling. Wrap wires around a pencil to keep them from falling back into the wall as shown in Fig. 2.

WIRES THROUG WALL OPENING

M5136

Fig. 2. Wrapping wires around pencil.

Replacing Clock With C or C1 Clock Terminals

If you are replacing a Honeywell Chronotherm® Thermostat, you may find one or two wires that go to the C or C1 clock terminals on the Chronotherm® Thermostat wiring wallplate. Do not allow them to touch, or you can damage your transformer. Disconnect the wires and wrap them separately using electrical tape; do not wrap them together. Place the wires to avoid interfering with the new thermostat operation. Record the colors and terminal designation labels of the remaining wires.

Six or More Wires

If there are six or more wires connected to the thermostat (excluding clock wires attached to terminals), you probably have a variation of a multistage heat pump or other multistage system. The thermostat is not compatible with such systems, so return the product to your retailer. For information about which programmable thermostats work with your system, call the Honeywell Customer Relations Center at 1-800-468-1502.

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CT500 ELECTRONIC THERMOSTAT

L (

Three Thermostat Wires

If you have three wires for heating only and can operate the fan using the Fan On switch, this thermostat works with your system. However, some hot water (zoned) heating systems have three thermostat wires. The thermostat works only if you install an isolating relay on these systems. For details, contact your local heating and/or air conditioning contractor.

3 MOUNT WALLPLATE

IMPORTANT

Level for appearance only. The thermostat functions normally, even when not mounted level.

❑ Position the decorator cover plate and wallplate on

the wall. Level the wallplate for appearance, if desired. Use a pencil to mark the two mounting holes that best fit the application. See Fig. 3

5-3/4 IN. x 5-3/4 IN. DECORATOR COVER PLATE

WALL

ANCHORS (2)

CT500A

Y G R

24V

HEATING PRIMARY CONTROL

system.

HEATING PRIMARY CONTROL

HOT)

24V

POWER SUPPLY. PROVIDE DISCONNECT MEANS AND

OVERLOAD PROTECTION AS REQUIRED.

Fig. 4. CT500 wiring diagram, 4-wire heat/cool

CT500A

1 HOT)

POWER SUPPLY. PROVIDE DISCONNECT MEANS

AND OVERLOAD PROTECTION AS REQUIRED.

FAN RELAY

COOLING CONTACTOR

M14872

M1487

3-7/8 IN. x 3-7/8 IN. DECORATOR COVER PLATE (SELECT MODELS). DRILL 3/16 INCH HOLES (IF DRYWALL) OR 7/32 (PLASTER OR WOOD)

WHEN USING WALL ANCHORS.

Fig. 3. Mounting decorator cover plate and wallplate

❑ Remove the decorator cover plate and wallplate from

the wall, and drill two 3/16-in. holes in the wall (if drywall). For firmer wall material such as plaster or wood, drill 7/32-in. holes. Gently tap provided anchors into the drilled holes until flush with the wall.

❑ Reposition the decorator cover plate and wallplate,

pulling wires through the wiring opening. Loosely insert the mounting screws into the holes.

❑ Level for appearance only; the thermostat functions

correctly, even when not level. Tighten the mounting screws.

to the wall.

4 WIRE WALLPLATE TERMINALS

The CT500 Thermostat is powered through the heating/ cooling system and is adaptable to most 4-wire, 18 to 30 Vac heating-cooling systems. Refer to Fig. 4 and 5 for typical system wiring diagrams.

M14871

Fig. 5. CT500 wiring diagram, 2-wire, heat-only

IMPORTANT

Use 18-gauge maximum wire to wire the thermostat.

All wiring must comply with local electrical codes and ordinances. If unsure about household wiring procedures, call your local heating and air conditioning contractor.

Refer to the wiring labels you placed on the wires when you removed your old thermostat.

❑ Match the letter of your old thermostat wire with the

terminal of the corresponding letter on your new thermostat. See Fig. 6.

NOTE: To ensure correct mounting of the thermostat,

restrict all wiring to the left side of the terminals.

❑ Loosen the terminal screws and slip each wire

beneath its matching terminal. The shape of the terminals permit insertion of straight or wraparound connections. See Fig. 7. Tighten the terminals.

❑ Plug the hole in the wall with insulation to help prevent

drafts from adversely affecting thermostat operation.

system.

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