The tekmarNet®4 thermostat 542 operates one stage of heating equipment. The 542 can operate as a stand alone device,
or communicate with a group of tekmarNet®4 thermostats.
A tN4 System Control is a control, not a thermostat, that
the 542 thermostat connects to through the tN4 bus. All
tN4 compatible Outdoor Reset Modules are tN4 System
Controls.
• If the thermostat is connected to a tN4 System Control,
set the tN4 System Control DIP switch to tN4 System
Control (down position).
• If the thermostat is not connected to a tN4 System
Control, set the tN4 System Control DIP switch to None
(up position).
Lock / Unlock (DIP Switch #1)
Use the Lock / Unlock DIP switch to lock or unlock the
Access Level of the 542.
• To unlock the Access Level, set the DIP switch to the
unlocked (down) position.
• To lock the Access Level, set the DIP switch to the locked
(up) position. Once locked, a padlock is displayed in the
lower right corner of the display and the Access Level
cannot be changed.
Note: The tN4 System Control’s Lock / Unlock DIP switch
overrides the Lock / Unlock DIP switch on the 542. Set
the tN4 System Control’s Lock / Unlock DIP switch to the
Unlock position before Access Levels can be changed on
the thermostat.
The Access Level restricts the number of Menus, Items
and Adjustments that can be accessed by the user. The
Access Level setting is found in the Miscellaneous (MISC)
menu. Select the appropriate access level for the people
who work with the thermostat on a regular basis.
The 542 has five Access Levels:
• Advanced (ADV): access to all settings
• Installer (INST): settings required for installation
• User (USER): for property owners
• Limited (LTD): limited temperature adjustment
• Secure (SEC): for commercial and public installations
Display
Menu Field
Displays the
current menu
For more information, see the Misc (Miscellaneous) Menu
section.
In the following menu tables, the access level the item is
visible in is shown in the access column.
To adjust the Access Level:
1. Set the Unlock / Lock DIP switch to the unlock position.
If a tN4 System Control is connected to the 542, the
Unlock / Lock DIP switch on the tN4 System Control
must be set to the unlock position.
2. Use the Menu button to select the Misc menu.
3. Use the Item button to select the Access menu item.
4. Use the Up and Down button to select the required
Access Level.
Item Field
Displays an abbreviated
name of the selected item
Status Field
Displays the current status
of the control’s inputs,
outputs and operation
Symbols Description
MODE OF OPERATION
Displays whether the device is in heating
or off mode.
FIRST STAGE HEAT
First stage heating is operating.
SCHEDULE MASTER
Indicates that this thermostat is a
schedule master.
tN4 COMMUNICATION
A tN4 network is detected.
Number Field
Displays the current value
of the selected item
OPTIMUM START / STOP
The Optimum Start or Optimum Stop
feature is active.
WARNING
An error is present.
TEMPORARY HOLD
The temperature has been temporarily
adjusted from the scheduled event.
SCHEDULED EVENT
Displays the current scheduled event.
LOCK
The Access Levels are locked. A menu
option is visible but not adjustable.
Use the User Interface available on the Liquid Crystal Display
(LCD) to setup and monitor the operation of the thermostat.
Use the four push buttons below the LCD (Menu, Item, Up,
Down) to select settings. As you enter settings, record the
settings in the Job Record J 542.
Menu
The menus display in the Menu Field at the left of the
LCD.
Six menus are available:
• View
• Adjust
• Time
• Scene
• Schedule
• Miscellaneous
To select a menu, press and release the Menu button.
Item
In each menu, a group of items can be selected. The
abbreviated name of the selected item displays in the Item
field of the LCD display.
• To view the next available item, press and release the
Item button.
• To view the previous item, hold down the Item button
and press and release the Up button.
Adjusting a Setting
To adjust a setting:
1. Use the Menu button to select the appropriate menu.
2. Use the Item button to select a menu item.
3. Use the Up or Down button to adjust the setting.
Default Item
• To set the default item in the View Menu, display the
item for more than five seconds.
After navigating menus, the display reverts back to the
default item after 60 seconds of button inactivity.
Copy Settings
To save time in setting thermostats, you can copy the settings
from one tN4 thermostat to a second tN4 thermostat.
Refer to the COPY item in the Misc menu on page 15.
Select the minimum floor temperature for each
event.
Note: This item is only available when Sensor 1 or 2
is set to Floor. At the Limited Access Level, you can
only adjust the temperature +/-3°F (1.5°C) from the
last setting.
FLOOR MAXIMUM
Maximum floor temperature.
Note: This item is only available when Sensor 1 or
2 is set to Floor.
SENSOR 1 SECTION A
Select the type of sensor connected to the auxiliary
sensor input 1.
SECTION A
SECTION A
ADJUST MENU
OFF, ROOM,
FLOR (Floor),
OUT (Outdoor)
Default = OFF
OFF, ON
Default = ON
SYNC, AUTO
2 to 12
Default = AUTO
CTRL, HRF1, HRF2,
COIL, CONV, RAD,
BASE, OTHR
Default =CTRL
INST
ADV
INST
ADV
ADV
INST
ADV
SENSOR 2 SECTION A
Select the type of sensor connected to auxiliary
sensor input 2.
ROOM SENSORSECTION A
Selects whether the built-in room sensor is functional.
HEAT CYCLES PER HOUR
Select the number of heating cycles per hour. SYNC
results in 5 CPH. All tN4 thermostats that are connected
and have the SYNC setting selected synchronize their
cycle to the same starting time.
Note: This item is only available when the tN4 System
Control DIP switch is set to None.
HEAT 1 TERMINAL SECTION E
Select the type of heating terminal.
Note: If CTRL is selected, the terminal unit selected
Select whether the system, primary, or mixing pump
on a tN4 System Control must operate while the heat
is operating.
Note: This item is only available when the H1 Terminal
item is set to CTRL, HRF1, HRF2, Fan Coil, Convector,
Radiator, or Baseboard.
HEAT 1 DELAY SECTION F
Select whether the system, primary, or mixing pump
on a tN4 System Control is delayed to allow a thermal
motor zone valve to open. Select On for thermal motor,
select Off for zone pump or motorized zone valve.
Note: This item is only available when the H1 Terminal
item is set to CTRL, HRF1, HRF2, Fan Coil, Convector,
Radiator, or Baseboard.
COOL MEMBER SECTION G
Select the cool group of which this thermostat is a
member. Select None if this thermostat is not a cool
group member.
Note: This item is only available when the thermostat
is connected to a tN4 network.
WARM WEATHER SHUT DOWNSECTION N
Set the outdoor temperature at which warm weather
shutdown occurs. Select whether the thermostat
follows the tN4 System Control’s or the zone’s WWSD
for scheduled events.
WWSD OCCUPIED AND WAKE SECTION N
Set the Warm Weather Shut Down (WWSD) temperature
during Occupied and Wake events.
Note: This item is only available when WWSD is set
to Zone.
SECTION F
40 to 100°F, OFF
(4.5 to 38.0°C, OFF)
Default = 60°F
(15.5°C)
ON, OFF
Default = ON
After the last item, the control returns to the first item in the menu.