tekmar 545 Thermostat Installation - Manual (Page 35)

35 of 40 © 2008 D 545 - 07/08
Offset Section Q
Warm Weather Shut Down Section R
This thermostat uses a high quality temperature thermistor
and is calibrated to accurately read the room temperature.
However, if you wish to fine tune the measured room temperature, use the Offset feature to increase or decrease
room temperature in tenths of degrees.
•
• Locate the Offset setting in the Misc menu.
The Warm Weather Shut Down (WWSD) feature prevents
the heating system (including floor minimum temperatures)
from operating after the outdoor temperature exceeds the
WWSD temperature setting. You can follow the tN4 System Control’s WWSD or you can set WWSD temperatures for
the Wake and Occupied events, and for the Unoccupied
and Sleep events.
•
• Locate the WWSD setting in the Adjust menu.
Cold Weather Shut Down Section S
The Cold Weather Shut Down (CWSD) feature prevents the
cooling system from operating after the outdoor temperature
falls below the CWSD temperature setting. You can set CWSD temperatures for the Wake and Occupied events,
and for the Unoccupied and Sleep events.
•
• Locate the CWSD setting in the Adjust menu.
Units of Temperature Section T
The thermostat can display temperatures in either
Fahrenheit (°F) or in Celsius (°C). • Locate the units setting in the Misc menu.
Backlight Section U
Use the thermostat’s backlight to increase the visibility of
the display. You can set the backlight to On, Temporary,
or Off. If you select On, the backlight remains permanently
on. If you select Temporary, the backlight comes on for 30 seconds when a button is pressed. If you select Off the
backlight remains permanently off. By default, the backlight
is set to Temporary.
• Locate the Backlite setting in the Misc menu.
tN4 Address Section V
When connected to other tN4 devices through a tN4 bus,
the thermostat is automatically assigned a network address.
The tN4 address is useful when trying to correct bus error
open and short circuits.
The address includes the bus water temperature designation
and a device number. The bus water temperature designations
available are Boiler, Mix 1, Mix 2, etc. The device number
can range from 1 to 24. If the thermostat is operating as a
member of a thermostat-only network, the thermostat does
not have an address and the address item in the MISC
menu is not available.
The device number determines the heating priority for each
zone. A thermostat with device number 1 has a higher priority
than device number 24. The tN4 address allows the tN4
system control to shut off low priority zonezs when the heat
source is unable to heat all zones simultaneously. In some
cases, the installer may want to change the thermostat’s
address in order to change the thermostat’s priority relative
to other thermostats.
Note: Keep track of manually set tN4 addresses. When
a tN4 address is manually set, tN4 thermostats using the
Auto Address setting will automatically be assigned new
addresses.
If two thermostats are manually set to the same address, an
error message will appear. The error remains until one of
the addresses is manually changed to a vacant address.
Pump Exercising Section W
When connected to a tN4 system control, the thermostat
exercises the pump relays for 10 seconds every 3 days.
Exercising helps prevent pump seizure. While the thermostat
is exercising, the display shows “Test”. Exercising does not occur when:
•
• Mode of Operation is set to Off.
•
• Heat Source is set to Other.
•
• DIP switch 2 is set to None.