tekmar 421 Mixing Reset Module User Manual
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© 2007
D 421 - 08/07
Access Level
Boiler Sup / Ret
Use the Boiler Sensor Supply / Return DIP switch to select
the location of the boiler sensor.
•
• If the boiler sensor is located on the supply, this DIP
switch should be set to Sup. The 421 is the control that
determines the boiler water temperature. Set the boiler’s
aquastat at least 20°F (11.0°C) higher than the Boiler
Maximum setting.
•
• If the 421 provides a heat demand to an external boiler
control, this DIP switch must be set to Ret. Install the
boiler sensor on the return side of the boiler loop.
The boiler’s operating temperature is controlled by its
aquastat, or an external boiler reset control.
Off / Flushing
The Off / Flushing DIP switch selects whether the control
operates a Flushing feature. Heating systems that use
potable water require periodic flushing to prevent the water
from stagnating.
The flushing operation occurs if any zone has not operated
for 7 days. All zones, mixing device(s), and applicable
system pumps are turned on for 4 minutes.
•
• To activate the Flushing feature, set to Flushing.
•
• To deactivate the Flushing feature, set to Off.
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 control on a regular basis.
There are two Access Level settings:
•
• Installer (InS): This is the factory default setting. This
access level is sufficient for the normal set up of the
control.
•
• Advanced (Ad): All of the control settings are available
to the user.
In the following menu tables, the access level the item is
visible in is shown in the access column.