Stelpro STE241 User manual

INSSTE2410613
For further information or to consult this guide online,please visit
our website at www.stelpro.com
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USER’S GUIDE
STE241
LOW VOLTAGE
ELECTRONIC THERMOSTAT (24V)

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Before installing and operating this product, the owner and/or
installer must read, understand and follow these instructions and
keep them handy for future reference. If these instructions are
not followed, the warranty will be considered null and void and
the manufacturer deems no further responsibility for this product.
Moreover, the following instructions must be adhered to in order to
avoid personal injuries or property damages, serious injuries and
potentially fatal electric shocks. All electric connections must be

codes effective in your region. Do NOT connect this product to a
supply source other than 24 VAC and do not exceed the load limits
        
breaker or fuse. You must regularly clean dirt accumulations on the

install thermostat in a wet place. However, installing it in isolated
walls is allowed.
Note:
When a part of the product specication must be changed to improve
operability or other functions, priority is given to the product specication
itself. In such instances, the instruction manual may not entirely match all
the functions of the actual product.
Therefore, the actual product and packaging, as well as the name and
illustration, may differ from the manual.
The screen/LCD display shown as an example in this manual may be
different from the actual screen/LCD display.
WARNING

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The STE241 low voltage electronic thermostat (24 V) is designed to control
relays (electronic or not). The allowed resistive maximum load is 12 W at 24
V (0.5 A). Then, relays (electronic or not) connected to the thermostat can
control electric baseboards with or without fans, convectors, fan heaters and
electric furnaces. This thermostat can be connected to Stelpro relays (with or
without transformers). Moreover, the triac contact is really quiet.
This thermostat is not compatible with the following
installations:
• resistive load of more than 12 W at 24 VAC (0.5 A)
Parts supplied:
• one (1) thermostat
• two (2) mounting screws
Selection of thermostat location
The thermostat must be mounted on a wall facing the heating unit, at
around 1.5 m (5 feet) above the oor level, on a section of the wall exempt
from pipes or air ducts.
Do not install the thermostat in a location where temperature measurements
could be altered. For example:
• close to a window, on an external wall, or close to a door leading outside
• exposed directly to the light or heat of the Sun, a lamp, a replace or any
other heat source
• close or in front of an air outlet
• close to concealed ducts or a chimney
• in a location with poor air ow (e.g. behind a door), or with frequent air
drafts conditions (e.g. head of stairs).
DESCRIPTION
INSTALLATION

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Thermostat mounting and connection
1. Ensure that the air vents of the thermostat are clean and clear of any
obstruction.
2. Using a screwdriver, loosen the screw retaining the mounting base and
front part of the thermostat. Remove the front part of the thermostat from
the mounting base by tilting it upward.
N.B. The following photos show a connection box installation as a reference
only. A connection box is not necessary or required.
3. Align and secure the mounting base using the two screws supplied.

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4. Connect the wires coming from the 24 VAC power source following the
appropriate diagram below:
One baseboard with a STELPRO RE-153T electronic relay with a 24 VAC
transformer.
Two baseboards, with one connected to a Stelpro RE-153T electronic
thermostat with a 24 VAC transformer, and with the second baseboard
connected to a Stelpro RE-153 electronic thermostat without a 24 VAC
transformer.

BLACK BLACK
BLACK
BLACK
ELECTRIC RELAY
WITH TRANSFORMER
ELECTRIC RELAY
WITHOUT TRANSFORMER
POWER
WIRES
SIGNALS
BLUE
BLUE
BLUE
RED
WHITE
BLACK BLACK
ELECTRIC RELAY
WITH TRANSFORMER
POWER
WIRES
SIGNALS
BLUE
RED
WHITE


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Standard 24 VAC power source (24 VAC transformer)
NOTE: the color of the wires can change according to the electronic relays
that are used. Connection diagrams in this guide are only examples.
5. Reinstall the front part of the thermostat on the mounting base and
tighten the screw at the bottom of the unit.
6. Turn on the power.
7. Set the thermostat to the desired setting (see the following section).

TRANSFORMER
24 VAC
PRIMARY
SECONDARY
CONTACTOR
OR RELAY

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Powering on for the first time
When powering on for the rst time, the thermostat is initially set to ‘Day’
mode. The temperature is displayed in Celsius and is set at 21 degrees
by default.
Temperature set points
The gures displayed above the pictogram indicate the temperature set
point. It can be displayed in degrees Celsius or Fahrenheit (see “Display in
degrees Celsius/Fahrenheit”).
To adjust the set point, just press down the top button to increase the value,
or the bottom button to decrease it. Set points can be adjusted by increments
of 0.5°C or 1°F. To quickly scroll through the set point values, press and hold
down the button. The minimum set point is 3°C (37°F), and the maximum
set point is 30°C (86°F). In Day mode, you can turn off the thermostat by
lowering the set point below 3°C. The set point value displayed will be --.-,
and heating system start up will be impossible.
OPERATION
Ambient
temperature
timer
Heating
power
used
indicator
Smart mode
Mode Sécurité
Fan mode
Top button
Pictograms
Frost-free
warning
Night mode
Day mode
Bottom button

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Day mode and Night mode
The thermostat includes a Day mode and a Night mode, both of them
having their own independently adjustable and recorded set point. When
switching from one mode to the other, the system will automatically use the
temperature set point corresponding to the Day/Night mode selected. The
standard factory set point adjustment is 21°C (70°F) for the Day mode, and
18°C (64°F) for the Night mode.
The current Day/Night mode selection is indicated on the display by the
Sun or Moon icon. In order to manually switch from one mode to the other,
simultaneously press down the two buttons and release them immediately.
Night mode timer
The Night mode features a timer that automatically returns to the Day mode
after a selectable time period. This timer allows the temporary use of a
temperature set point. The standard factory adjustment of the timer is 8
hours. With this adjustment, the thermostat automatically returns to Day
mode 8 hours after being switched to the Night mode.
For example, if you want a night temperature lower than the day
temperature, both Day/Night modes set points will rst have to be set at
the desired temperatures. Before bedtime, the Night mode temperature set
point will be activated by switching manually to the Night mode. The timer
is set for the duration of the night. The thermostat will automatically return
to the Day mode at the end of the night, and the Day mode temperature set
point, which is higher, will become effective at this time.
Night mode timer adjustment procedure
1. If necessary, adjust the Day/Night mode set points at the desired
temperatures. If needed, switch from one mode to the other by
simultaneously pressing down the two buttons and releasing them
immediately.
2. From the Night mode, simultaneously press down the two buttons for
more than 3 seconds until the Moon icon blinks and the letter H appears.
3. If needed, adjust the timer by pressing down the top button to increase
the value, or the bottom button to decrease it. The adjustment range is
from 1 hour to 999 hours. To quickly scroll through timer values, press
and hold down the button.
4. When the adjustment is completed, release the buttons and wait for
5 seconds to exit the adjustment function.

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N.B. The Night mode timer will be automatically reinitialized to the latest
recorded value when switching from the Day mode to the Night mode. It is
not necessary to readjust the timer every time you switch to the Night mode.
The timer is also reinitialized when this value is adjusted.
Once the timer has completed its cycle and when the thermostat is in the
Day mode, you must manually return to the Night mode. If you want to
automatically return to the Night mode, the Smart mode must be selected.
Smart mode
The Smart mode, which is associated to the Night mode timer, allows
alternating between the Day/Night modes and the two corresponding set
points over a 24-hour period. Once activated, this mode allows an automatic
return to the Night mode after 24 hours. The Smart mode allows you to
dene two periods in a single day with different set points.
For example, if the Smart mode is activated and the Night mode timer is set
at 8 hours, the thermostat will be operating in the Night mode for 8 hours at
the night temperature set point. Then, it will return to the Day mode for 16
hours operating at the day temperature set point. At the end of the 24-hour
cycle, the thermostat will return to the Night mode, and the cycle will start
again. The 24-hour cycle starts with the Night mode as soon as the Smart
mode is activated. The Smart mode activation should be made when you
want to return to the Night mode. The normal course of a cycle in the Smart
mode is as follows:
1. Night mode: activated for the duration of the Night mode timer cycle. It
returns to the Day mode when the timer cycle is completed.
2. Day mode: activated for the remaining time of the 24-hour cycle. It returns
to the Night mode at the end of the 24-hour cycle.
Adjustment procedure of the Smart mode:
1. If necessary, adjust the Day/Night set point at the desired temperatures.
If needed, switch from one mode to the other by simultaneously pressing
down the two buttons and releasing them immediately.
2. From the Night mode, simultaneously press down the two buttons for
more than 3 seconds. If needed, adjust the timer by pressing down the
top button to increase the value, or the bottom button to decrease it. The
Night mode timer adjustment range is from 1 hour to 23 hours in the
Smart mode. To quickly scroll through the timer values, press and hold
the bottom button. 
hours, it will be impossible to activate the Smart mode and if it was
activated, the Smart mode will be deactivated.

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3. Activate the Smart mode by simultaneously pressing down the two
buttons for at least 3 seconds. The icon will appear. If the Smart
mode was already activated, the same procedure should be used to
deactivate it.
4. When the adjustment is completed, release the buttons and wait for 5
seconds to exit the adjustment function.
N.B. It is always possible to manually change the Day/Night mode
during a 24-hour cycle. However, any manual return to the Night mode
will re-initialize the Night mode timer to the latest value recorded, which
modies the cycle in progress. In all cases, at the end of the 24-hour cycle,
the thermostat will return to the Night mode and start a new cycle. It is thus
not necessary to readjust the Smart mode when a manual change is made
to the Day/Night mode.
When turning back on after being powered off (because of a power outage,
for example), the automatization of the Day/Night modes is deactivated,
and, if previously activated, the icon will blink. The blinking will stop as
soon as you press down a button.
Display in degrees Celsius/Fahrenheit
The thermostat can display the ambient temperature and the set point in
degrees Celsius (standard factory setting) or Fahrenheit.
Selection procedure for degree Celsius/Fahrenheit display.
1. From the Day mode, simultaneously press down the two buttons for more
than 3 seconds.
2. Press down the top button to switch from the degrees Celsius to the
degrees Fahrenheit, and conversely. The degree Celsius or Fahrenheit
symbol will be displayed.
3. When the adjustment is completed, release the buttons and wait for 5
seconds to exit the adjustment function.
Long cycle/Short cycle mode
The Long/Short cycle activation is similar to the Celsius/Fahrenheit degrees
adjustment. To switch from long cycle heating (15 minutes) to a short cycle
heating (15 seconds), you must simultaneously press down both buttons
during 3 seconds in Day mode. After 3 seconds, the C or F icon will blink.
Release the buttons. The screen then displays CC to indicate short cycle or
CL to indicate the long cycle. To switch from one mode to the other, press
down the bottom button. Once the adjustment done, exit this mode by not
pressing down any button for 5 seconds.

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Minimum ON/OFF time selection in Long cycle
In Long cycle, you can adjust the minimum ON/OFF time (e.g. the minimum
time between the start and the shut down of the heating). First, activate
the Long/Short cycle mode as described in the previous section. Press
down the bottom button for 3 seconds until the time in seconds appears
on the screen. Release the button. Adjst the minimum time from 90 to 405
seconds, by increments of 45 seconds (factory setting = 180 seconds).
Please note that the Long cycle (CL) is automatically activated when we
enter in the minimum ON/OFF time selection mode. Once the adjustment
done, exit this mode by not pressing down any button for 5 seconds.
Heating Power Indicator
The level of power used to maintain the temperature at the set point
is expressed as a percentage indicated by the number of bars in the
thermometer displayed. The heating power used is displayed as follows:
4 bars = 75 % to 100 %
3 bars = 50 % to 75 %
2 bars = 25 % to 50 %
1 bar = 1 % to 25 %
0 bar = no heat
Frost-free warning
The Snowake icon is displayed when the temperature set point is between
3°C (37°F) and 5°C (41°F). A minimum temperature will be maintained to
ensure frost control.
Security mode
It is possible to impose a maximum temperature set point by activating this
mode. Then, it becomes impossible to exceed this set point, regardless of
the current mode (Day/Night). However, it is still possible to lower the set
point at your discretion.
Procedures to activate the Security mode
1. To activate the Security mode, from the Day mode adjust the day set point
to the desired maximum temperature.
2. From the Day mode, simultaneously press down the two buttons for more
than 13 seconds, until the icon displays (note that the °C or °F will
appear after 3 seconds continue to keep both buttons pressed down or
you will nd yourself in the degree adjustment mode or in Fan mode).
3. Release the buttons. The thermostat is now locked.

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Procedures to deactivate the Security mode
1. To deactivate Security mode, start by cutting thermostat power at circuit
breaker and wait at least 20 seconds.
2. Turn thermostat power back on and the icon will blink for a maximum
of 5 minutes.
3. Simultaneously press both buttons for 13 seconds. (Note that the
pictogram displaying the degrees (C or F) will blink after three seconds, it
is important to keep the two buttons pressed down to avoid switching to
the adjustment or Fan mode). After 13 seconds, the icon will disappear
and the degrees symbol (C or F) will stop blinking; indicating that the
Security mode is deactivated. Release the buttons.
Fan mode
The activation of the Fan mode is similar to the Celsius/Fahrenheit
adjustment. To activate or deactivate Fan mode, you must press down both
buttons simultaneously for at least 3 seconds while in Day mode. Once the
3 seconds have passed, C or F will blink. At this point, release the buttons.
You must then press down on the bottom button to activate or deactivate the
Fan mode. The fan pictogram will turn on or off depending on the case.
When Fan mode is activated, the stop or minimum heating time (OFF/
ON) for a complete 15 minute cycle is established at 5 minutes. This is
done to limit the amount of time the thermostat will turn on or off. Also, if
the thermostat reaches a differential superior or inferior to the 2 degrees
requested, it will shut off before the end of the minimum heating time of
5 minutes. The deactivation of the Fan mode will cause the thermostat to
go back to the heating cycle previously programmed. Once the adjustment
nished, you can exit the Fan mode by not pressing down on any buttons
for 5 seconds.
Saving the parameters and power failures
The thermostat saves some parameters in a non-volatile memory to be able
to recover them after being shut off (a power failure, for example). These
parameters are the Day/Night settings, the Smart mode, the state of the
Security mode, the maximum setting of the Security mode, the Celsius/
Fahrenheit mode, the Fan mode, the ideal changeover time of the relay and
the number of minutes associated to a heating cycle, the number of hours
of the night time-switch, the number of hours remaining on the night time-
switch and the day/night current. These parameters are saved every minute
if any changes are made, except for the Day/Night mode and the remaining
time left on the time-switch. These are saved only if the Security mode had
not been activated.

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Please note that the Smart mode is not automatically reactivated when
thermostat is turned on. The icon blinks to warn the user that the mode
was previously activated when thermostat was shut off but is no longer
active.
Furthermore, when power is shut off, the existing Day/Night mode is
recovered only if the Smart mode was previously deactivated. In the opposite
case, the Day mode is automatically reactivated. The Security mode is also
reactivated if it was activated before being shut off. However, the icon will
blink for 5 minutes, during which it is possible to deactivate the Security
mode by pressing down on the top and bottom buttons simultaneously for
13 seconds. If this is not done, the Security mode will stay activated and the
icon will stop blinking.

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Problem DeFeCTIVe PArT or PArT
To CHeCK
Heating is always on
• Check if the thermostat is
properly connected. Refer to
the installation section.
Heating does not run even if the
thermostat indicates it is on
• Check if the thermostat is
properly connected. Refer to
the installation section.
The display does not come on
• Check if the thermostat is
properly connected. Refer
to the installation section.
Check the power supply at
the electrical panel. Check if
the heating unit has a switch.
If so, ensure that this switch is
turned on.
The display turns off a few minutes
and then turns on again
• The thermal protection of
the heating unit has opened
due to overheating. Check
if the heating unit is in good
condition of operation and
that clearance around the
appliance is according to the
manufacturer’s specifications.
The display has low contrast when
heating is on
• The load is lower than the
minimum load. Install a heating
unit that is within the load limits
of the thermostat.
The displayed ambient
temperature is incorrect
• Check the presence of an air
stream or a heat source near
the thermostat, and correct the
situation.
The display indicates E1 or E2 • Faulty thermal sensor. Contact
the customer service.
TROUBLESHOOTING

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Weak luminosity of the display
• Possibility of a bad contact.
Check thermostat wirings.
Refer to the installation section.
If you are unable to solve the problem after having veried these points,
please communicate with our customer service. Consult our website for the
phone numbers.
Supply voltage:
24 VAC, 50/60 Hz
Maximum electrical
current with a resistive
load:
0.5 A
12 W @ 24 VAC
Temperature display
range:
3 °C to 40 °C (37 °F to 99.5 °F)
Temperature display
resolution:
0.5 °C (0.5 °F)
Temperature set point
range:
3 °C to 30 °C (37 °F to 86 °F)
Temperature set point
increments:
0.5 °C (1 °F)
Storage temperature:
-40 °C to 50 °C (-104 °F to 122 °F)
Outlets
A 4-position connector is located at
the back of the thermostat.
C: Inlet 1 of ther 24 VAC power
W: Inlet 2 of the power
R: Inlet 2 of the VAC power
Compatible with Stepro electronic
relays
TECHNICAL SPECIFICATIONS

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
LIMITED WARRANTY LIMITED WARRANTY
LIMITED WARRANTY LIMITED WARRANTY
LIMITED WARRANTY LIMITED WARRANTY LIMITED WARRANTY LIMITED
LIMITED WARRANTY LIMITED WARRANTY LIMITED WARRANTY LIMITED
LIMITED WARRANTY
This unit has a 3-year warranty. If at any time during this period
the unit becomes defective, it must be returned to its place of
purchase with the invoice copy, or simply contact our customer
service department (with an invoice copy in hand). In order for
the warranty to be valid, the unit must have been installed
and used according to instructions. If the installer or the user
modies the unit, he will be held responsible for any damage
resulting from this modication. The warranty is limited to the
factory repair or the replacement of the unit, and does not cover the
cost of disconnection, transport, and installation.
E-mail: [e-mail]
Web site: www.stelpro.com