AERCO KC1000 Heater 2002 - Manual (Page 34)

INITIAL START-UP
4-6
6. Reinstall the cap and gasket back on the
regulator. Tighten the cap using a screw-
driver or wrench.
7. Remove all of the manometers and barbed
fittings and reinstall the pipe plugs using a
suitable thread compound.
8. Remove the combustion analyzer probe
from the vent hole. Seal the probe hole and
replace the vent connection cover.
9. Replace the unit’s panels and hood.
4.6 TEMPERATURE CONTROL
CALIBRATION
Although the unit comes factory set and
calibrated for a 130°
F setpoint it is usually
necessary to recalibrate temperature control.
There are two primary adjustments for
performing temperature calibration. These are
Min Load Adj and Max Load Adj (minimum and
maximum load adjustment).
Adjustments to these settings are made at
minimum and maximum load conditions and
should be made in small increments from 1 to 3
degrees. After making an adjustment, outlet
water temperature must be allowed to settle for
several minutes prior to making further
adjustments.
When calibrating temperature control, observe
the following:
1. The unit must be in the Auto mode of
operation.
2. The Outlet Feedback option in the Tuning
Menu must be off while performing calibra-
tion.
3. Monitor the
OUTLET T EMPERATURE dis-
play and
FIRE R ATE bar-graph display to
set load conditions and see the effect of
adjustments.
4. Perform the calibration using the Tuning
Menu of the Control Box.
5. Make small adjustments and allow time be-
tween adjustments for the outlet temperature
to stabilize.
6. Maintain water flow as constant as possible
during these adjustments.
7. Ensure that recirculation loops are opera-
tional while the calibration is being
performed.
4.6.1 SETTING THE OUTLET WATER
TEMPERATURE SETPOINT
The setpoint temperature of the unit may be
changed by following the procedure below.
However, once a setpoint has been changed,
recalibration may be necessary. The tempera-
ture calibration procedures are provided in
paragraphs 4.6.2 and 4.6.3
To adjust the unit’s setpoint, proceed as follows:
1. Press the
MENU key until Configuration
Menu is displayed.
2. Press the
▲ or ▼ arrow key until Internal
Setpt is displayed along with the present
setpoint temperature.
3. To change the setpoint, press the
CHANGE
key. The display will begin to flash.
4. Press the
▲ or ▼ arrow key until the desired
setpoint is displayed.
5. Press the ENTER key to save the change.
4.6.2 MINIMUM LOAD ADJUSTMENT
With the unit in operation, check the temperature
control at minimum load as follows:
1. While monitoring the
FIRE RATE display,
create a minimum load on the system that
will yield a steady fire rate between 25% and
35%.
NOTE:
It may be desirable to shut off the outlet valve and
use the hose bib to simulate a minimum flow load
condition.
2. Wait several minutes to allow the outlet
temperature to stabilize under load
conditions.
3. Once stabilized, the
OUTLET
TEMPERATURE display should read no
more than 2 to 3 degrees above the unit’s
setpoint.
4. If the outlet temperature is stabilized,
proceed to the Maximum Load Adjustment
procedure in paragraph 4.6.3. If the unit is
not stabilized, proceed to step 5.
5. Press the
MENU key and select the Tuning
Menu.