1
Service
20
Service Manual
1
Service
Boost temperature
If a SH demand lasts longer than the programmed time delay
setting (F9) 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 (0°C) to 45°F (25°C). The default value is
0°F (0°C). This feature will be active if this parameter is set to
anything other than 0°F (0°C).
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.
G: Anti-cycling
Anti-cycling time
Once a SH demand has been satisfied, a set amount of time
must elapse before the control will respond to a new SH
demand. The control will block the new heat demand and
anti-cycling will be shown in the display until the time has
elapsed or the water temperature drops below parameter G2.
This parameter can be changed by the installer by accessing
parameter
G1
. The time range for this parameter is 0 minutes
to 40 minutes. The default value is 1 minute.
Inlet temperature differential for ending anti-cycling
The control will bypass the anti-cycling time if the water
temperature drops too quickly. The control will use the water
temperature the boiler was at when it shut off as the starting
point. If the temperature drops below the temperature
parameter the control will abort anti-cycling and allow the
boiler to fire. This parameter can be changed by the installer
by accessing parameter
G2
. The temperature range of this
parameter is 0°F (0°C) to 54°F (30°C). The default value is
10°F (5°C).
Ramp delay on/off
When the ramp delay on/off parameter is active, the ramp
delay limits the boiler firing rate when a SH cycle has started.
There are six (6) limiting steps used to limit temperature
overshoot and short cycles, see FIG. 1-2 on page 21 of this
manual. This feature can be turned on or off depending on
the installation. This parameter can be changed by the
installer by accessing parameter
G3
. The control range of this
parameter is 0 = Off, 1 = Ramp Up Only, and 2 = Ramp Up
and Ramp Down. The default value is 0.
When ramp delay is active, additional parameters for ramp
delay operation will have to be adjusted. These can only be
accessed by the optional PC software. See the Knight Smart
System PC Program Instructions Manual for additional ramp
delay parameter information.
Summary of Contents for KNIGHT 399 - 800
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