AERCO KC1000 Low NOx Water Heater July 2011 - Manual (Page 37)

INITIAL START-UP
4-9
5. Make small adjustments and allow time
between adjustments for the outlet water
temperature to stabilize.
6. Maintain water flow as constant as possible
during these adjustments.
7. Ensure that recirculation loops are
operational 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
temperature 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 VALVE POSITION
display, create a minimum load on the
system that will yield a steady valve position
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 TEMPER-
ATURE 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.
6. Press the ▲ or ▼ arrow key until Min Load
Adj is displayed.
7. Press the CHANGE key. The display will
begin to flash.
8. Raise or lower the minimum load adjustment
in increments of one or two using the ▲ or
▼ arrow key. Increasing this value will
increase outlet water temperature, while
decreasing it will decrease outlet water
temperature.
9. Press ENTER to save the change. Allow
time for the system to stabilize between
adjustments
10. Repeat steps 5 through 9 as needed until
the temperature is stabilized at no more than
2 to 3 degrees above the setpoint.
4.6.3 MAXIMUM LOAD ADJUSTMENT
Check the temperature control at maximum load
as follows:
1. While monitoring the VALVE POSITION
display, create a maximum load on the
system that will yield a steady valve position
between 80% and 90%.
NOTE:
It may be necessary to open the outlet valve if it
was closed during minimum load adjustment to
obtain a sufficient flow rate for maximum
adjustment.
2. Wait several minutes to allow the outlet
water temperature to stabilize under load
conditions.
3. Once stabilized, the OUTLET TEMPER-
ATURE display should read no more than 2
to 3 degrees below the unit’s setpoint.
4. If the outlet temperature is stabilized, no
adjustment is necessary. If the unit is not
stabilized, proceed to step 5.
5. Press the MENU key and select the Tuning
Menu.
6. Press the ▲ or ▼ arrow key until Max
Load Adj is displayed.