tekmar 270 Boiler Control - Manual (Page 5)

5 of 24 © 2010 D 270 - 08/10
EXERCISING
The control has a built-in exercising feature that is selected through the Exercise / Off DIP switch. To enable the exercising feature
set the Exercise / Off DIP switch to Exercise. If exercising is enabled, the control ensures that each pump is operated at least
once every 3 days. If a pump has not been operated at least once every 3 days, the control turns on the output for 10 seconds.
This minimizes the possibility of the pump seizing during a long period of inactivity. While the control is exercising, the Test LED
flashes quickly.
Note: The exercising function does not work if power to the control or pumps is disconnected.
RUNNING TIMES
The control displays the accumulated running time of the boiler in the VIEW menu.
Resetting the Running Time
To reset the running time for the boiler, select the running time in the VIEW menu. Next press the and buttons simultaneously
until CLR is displayed.
FACTORY DEFAULTS
The control comes preset with several factory defaults. These are based on the terminal unit selection. To fine-tune building
requirements, these defaults may be changed.
To reload the factory default, power down the control and wait for 10 seconds. Power up the control while simultaneously
holding the Menu and buttons. An E01 error occurs forcing the installer to go through the ADJUST menu to ensure the
settings are correct.
BOILER MINIMUM
The boiler minimum is the lowest temperature that the control is
allowed to use as a boiler target temperature. During mild conditions,
if the control calculates a boiler target temperature that is below the
Boiler Minimum
setting, the boiler target temperature is adjusted to at
least the Boiler Minimum setting. During this condition, if the boiler is
operating, the minimum segment is turned on in the display when viewing
either the boiler supply temperature or the boiler target temperature. Set
the Boiler Minimum setting to the boiler manufacturer’s recommended
temperature.
BOILER MAXIMUM
The boiler maximum is the highest temperature that the control is
allowed to use as a boiler target temperature. If the control does target
the Boiler Maximum setting, and the boiler temperature is near the boiler
maximum temperature, the maximum segment will be displayed in the
LCD while either the boiler target temperature or the boiler temperature
is being viewed. At no time does the control operate the boiler above
248°F (120°C).
FIRE DELAY
The Fire Delay is the time delay that occurs between the time that the control
closes a stage contact to fire a stage and the burner fires for that stage.
MIN Segment On
MAX Segment
On
MAX Segment
On
Boiler
Contact Closes
Boiler
Fires
Fire
Delay
Time
BOILER TARGET TEMPERATURE
The boiler target temperature is determined by the type of demand received by the control. A boiler demand calculates a boiler
target based on the characterized heating curve settings and the outdoor air temperature. A DHW demand has a temperature
setting to which the boiler is operated to meet.
The control displays the temperature that it is currently trying to maintain as the boiler supply temperature. If the control does not
presently have a requirement for heat, it does not show a boiler target temperature. Instead, “– – –” is displayed in the LCD.
Section B: Boiler Operation