User’s Information Manual
15
4
SMART SYSTEM control module
(continued)
E: DHW settings
DHW boiler set point
When a DHW call for heat becomes active, the control will
use the DHW boiler set point to determine the firing rate of
the boiler based on the actual water temperature.
This
parameter can be changed by the installer by accessing
parameter
E1
. The temperature range of this parameter is
50°F to 190°F. The default value is 180°F.
SH/DHW switching time
The SH/DHW switching time parameter sets the length of
time the control will stay in DHW Mode when a SH call has
been received. After this time period has expired the control
will revert to SH Mode. If a DHW call is still active the timer
will reset. After the time period has expired the control will
revert back to DHW Mode. This will continue until one of
the demands has been satisfied.
This parameter can be
changed by the installer by accessing parameter
E2
. The time
range of this parameter is 10 minutes to 240 minutes. The
default value is 30 minutes.
F: Outdoor air reset
Outdoor air shutdown
When the outdoor air shutdown rises above this point, the
control will block all SH demands (DHW demands will still
be active). This parameter can be changed by the user or the
installer by accessing parameter
F5
. The temperature range of
this parameter is 0°F to 120°F. The default value is 80°F.
Outdoor air shutdown differential
The outdoor air shutdown differential parameter is the
number of degrees below parameter F5 the outdoor air
temperature must go before the boiler will respond to a SH
demand. This parameter can be changed by the user or the
installer by accessing parameter
F6
. The temperature range of
this parameter is 0°F to 90°F. The default value is 10°F.
Boost temperature
If a SH demand lasts longer than the programmed time delay
setting and there have been no DHW demands, the control
will increase the water temperature set point by the amount
in this parameter. If the SH demand continues through
another time period, the set point will be increased again.
This will continue until either the SH demand ends, a
maximum of 20 increases has occurred, or the maximum set
point has been reached. Once the SH demand has been
satisfied the set point will revert back to its calculated setting.
The boost temperature can be changed by the installer by
accessing parameter
F8
.
The temperature range of this
parameter is 0°F to 45°F. The default value is 0°F. This feature
will be active if this parameter is set to anything other than
0°F.
Boost time
The boost time parameter sets the amount of time that must
elapse with a SH demand before the water temperature set
point will be increased. This parameter can be changed by the
installer by accessing parameter
F9
. The time range for this
parameter is 1 minute to 60 minutes. The default value is 20
minutes.
