Honeywell CT1950 Leaflet

Automation and Control Solutions
Honeywell                              Honeywell Limited-Honeywell Limité e
1985 Douglas Drive North       35 Dynamic Drive
Golden Valley, MN  55422         Scarborough, Ontario 

MIV 4Z9 

G.H.  •  6/02  •  © Honeywell Limited 69-1644EF

™

12

cont’d

Scroll through the displays until the
screen shows the MOnday to FRiday
schedule with the WAKE, LEAVE
RETURN and SLEEP options

Follow the same programming 
proceedure as steps 8–12

Program SAturday and SUnday 
separately or use the “Copy From –
Copy To” feature (steps 13–16)

Note: Broken line outline indicates flashing characters

Your CT1950/CT1957 Programmable Electronic Line
Voltage Thermostat features digital temperature
sensing and control for energy efficient 
precision operation. It will provide the flexibility 
of 5-1-1 day or 7 day programming and 
exceptional comfort control of resistance-rated
heating equipment.The patented CoolSwitch™
design offers long service life.

Depending on local climate, night and day set-
back of space temperature can save up to 28%
of the energy used to heat a controlled zone.

According to the Electric Power Research
Institute, precision temperature control also offers
up to 12% energy saving during comfort periods
compared with conventional bi-metallic electric
heating thermostats.

14

When the thermostat is first powered up (or after 8 hours of continuous power loss), the display will blink for 2 seconds,
then undergo a self test, indicated by  

OOE

for 15 seconds. Once the display shows 1:00 pm flashing, the internal

checkout is complete, and the thermostat is ready to program.

To verify the thermostat is turning on the baseboard heater, repeatedly press the [+] key until the displayed setpoint
exceeds the room temperature. The [°] symbol should be flashing. Feel near the baseboard heating element and the unit
should be starting to generate heat.

Press and hold the PROG key and the thermostat will return to its former RUN mode.

13

Press and release FUNC key to activate
the HOLD mode.
Press and hold PROG key to return to
RUN mode.

MODELS: CT1950A/CT1957A - SPST; Makes heating circuit on temperature fall.

CT1950B - DPST; Makes heating circuit on temperature fall. Breaks both sides of 240 volt line with switch in "OFF" position.

Operating range: -20 to +104°F [-30 to +40°C], 5 to 95% RH, non-condensing.

7 to 27°C [45 to 80°F] in 1° increments. Factory set at 16°C [61°F] .

Patented CoolSwitch™ thyristor with relay conductor.

6" [150 mm] stranded copper leadwires suitable for connection to aluminum wiring if approved special service CO/ALR connectors are
used.

16 A (3800W)  maximum, 2 A (500W) minimum @ 240V, 60 Hz. (12 ft. of baseboard maximum)

Electronic thermistor.

2

•  This thermostat is a line voltage (240 Vac) control. Do not install it unless you are completely familiar and competent with house

wiring. If improperly handled, there can be a risk of 240 Volt electric shock hazard which may cause serious injury or death.

• The CT1950/CT1957 is rated for normal full load current on a dual residential 20 A circuit breaker or fuse block. Do not use on circuits

protected by higher-rated over-current protection devices. Some sustained fault conditions can cause product failure.

•  Do NOT connect to voltage different from device rating.

• Disconnect power supply before making wiring connections to prevent electrical shock or equipment damage.

•  All wiring must comply with applicable codes and ordinances.

•  Thermostats are designed to be used with appliances having a limit control.

• Maximum load for thermostat must not exceed 3800W, otherwise a potential fire hazard exists.

(ie. greater than 12 ft. of baseboard)

LOCATION: 
Install a vertical switch box for mounting the CT1950/CT1957 approximately 1.5 m (5 ft.) above the floor on an inside wall where the thermo-
stat will be subjected to average room temperature. The thermostat must be placed away from concealed warm or cold water pipes,
air ducts, or drafts from hallways, fireplaces or stairways to sense temperature properly. Do not place thermostat above heater.

3

Display DAY of the Week

Change DAY of the Week

Display HOUR of the Day

Change HOUR of the Day

7

Note; Broken line outline indicates flashing characters

Display MINUTE of the Day

Change MINUTE of the Day

7 Day Mode (factory default setting)

Scroll through to display showing the first
day of programming [beginning with
MOnday]  

Display WAKE time

8

1

Power supply. Provide disconnect means 
and overload protection as required.

2

Special service CO/ALR solderless 
connections must be used when 
connecting aluminum conductors; 
otherwise, a fire hazard may result.

3

Thermostat breaks heating circuit on
temperature rise.

4

Thermostat is designed to be used with 
appliances equipped with a limit control.

5

B Model thermostat breaks both sides of 
line with switch in OFF position

1. Disconnect power while installing.

Double check that thermostat is rated for voltage and amperage of load to be controlled.

2. Remove cover as needed by carefully prying at the top or bottom edge with a coin or slot screwdriver.

L1

T 1

L1

L1

ELECTRIC 
HEATER

L2

1

2

4

3

L1

T 1

ELECTRIC 
HEATER

2

4

3

RED

5

L2

T2

BLACK

BLACK

BLACK

1

BLACK

RED

L2

4

11

Press PROG key and continue –
(“b” will appear for b model only).

Press PROG key a second time to 
display C°. Use [+] key to change to 
F° if desired (or F° to C°) 

Press PROG key a third time to 
display  “5 1 1  d”; press [+] key to
change mode to 7-day programming
(or vice versa)

Press and hold both the PROG and FUNC
keys. Initially a random 4 digit/letter
display will occur.

FF      FF

36

3. When replacing an old line voltage wall thermostat, remove it carefully to avoid damage to the insulation on the wiring. Check the old 

insulation for cracks, nicks, or fraying and apply certified electrical tape where necessary to achieve adequate insulation, or replace 
the wires in an approved fashion.

4. Attach wires with solderless wire connectors approved for the size and number of wires to be connected. Be sure that all wire connectors

are tight.

CAUTION: Do not short 240 V supply wires with thermostat connected. This will damage the CT1950/CT1957 and void the warranty.

WARNING: To avoid risk of fire hazard, all connections to aluminum conductors must be made using approved 

CO/ALR solderless connectors.

5. Secure thermostat to the electrical box with captive mounting screws. Installation Hint: Prebend the solid conductors, then push them 

and the wire connectors into the electrical box before tightening the mounting screws.

6. Snap cover in place.

7. Turn power on.

!

5

Note: To exit the programming mode at any time, press

and hold the PROG key for 3 seconds.

Select and display the day to be copied,
e.g. MOnday

Press key to display COPY FROM

Select and display TUesday program period
(pressing key will display COPY TO)

Finally, press FUNC to enter this 
program.

Repeat process for each day copied

Broken line outline indicates
flashing characters

10

Change WAKE time in 10 minute 
increments

Display WAKE setpoint temperature

Change WAKE setpoint temperature

Display LEAVE time.
Repeat the adjustments suggested in
steps 9 - 11 for the LEAVE, RETURN and
SLEEP periods

9

On first power up, the thermostat display will show a self test 

status,

00 E

display for about 15 seconds, then go

blank for one second, followed by this display —
(broken line indicates 
section is flashing.) 

The thermostat will begin temperature 
control with the default setpoint at 61°F
(16°C) in the HOLD mode. It will continue to operate in this
manner until the user presses PROG and proceeds to set the
clock (Step 1) below.

Note: To Change display or functions (e.g. to °C or °F, or 
programming from 5-1-1 to 7-day) see instructions on 
Additional Functions, p. 11.

days (see Table 1 below). After the clock is set up, if the factory
set schedule is satisfactory, no more programming is required. The
thermostat will revert to normal RUN mode either by pressing and
holding the PROG key for 3 seconds, or left untouched for 5 min-
utes.

6

FACTORY SET PROGRAMMING
The thermostat is preset with a factory set schedule for 7

THERMOSTAT RESET The reset key is accessed by inserting
a bent paperclip or similar wire into the small hole next to
the [+] key (with cover removed). This will reset the clock
only, programmed schedule will be retained.

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Thermostat Programming. . . . . . . . . . . . . . . . . . . 6

Initial Power-Up . . . . . . . . . . . . . . . . . . . . . . 6

Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Schedule: 7 days . . . . . . . . . . . . . . . . . . . . . 8

5-1-1 days . . . . . . . . . . . . . . . . . . . . . . . . . 12

Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Additional Functions . . . . . . . . . . . . . . . . . . . . . 11

Change Display . . . . . . . . . . . . . . . . . . . . . 11

Temporary Program Override . . . . . . . . . . . 13

Indefinite Program Override . . . . . . . . . . . . 13

Copy Program From One Day to Another . . 10

Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Press and hold [+] or [-] key until TEMP
appears on screen; adjust temperature [+] or 
[-] as desired. Thermostat will return to normal
program status automatically in next period  

OLOAd

Connected load exceeded
3800W

Ensure that total wattage of baseboard connected do not exceed 3800W.
A fire hazard exists if wattage exceeds 3800W. Push reset key to clear
and reset clock.

06E

Power failure detected

Push reset key to clear and reset clock.

Missing segment or other abnormal display Push reset key to clear and reset clock. If problem persist call Honeywell.