AERCO KC Series Equipped with C-More Controller for Massachusetts Only - Manual (Page 37)

INITIAL START-UP
4-7
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 the outlet water temperature, while
decreasing it will decrease the 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 minimum 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
temperature to stabilize under load
conditions.
3. Once the temperature has stabilized, the
OUTLET TEMPERATURE 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.
7. Press the CHANGE key. The display will
begin to flash.
8. Raise or lower the maximum load
adjustment using the ▲ or ▼ arrow key.
Increasing this value will increase outlet
water temperature, while decreasing it will
decrease 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 2 to 3 degrees
below the setpoint.
11. If the outlet temperature does not maintain
setpoint after a reasonable amount of time
and adjustment, contact your local AERCO
representative.
NOTE:
After performing Temperature Calibration and
prior to placing the water heater in service, be
sure to turn the Outlet Feedback option in the
Tuning Menu back to ON.
4.7 OVER-TEMPERATURE LIMIT
SWITCH ADJUSTMENTS
There are two Over-Temperature Limit switches
that turn off the unit when the outlet water
temperature becomes too hot. The lower over-
temperature limit switch is adjustable and should
be adjusted 20°F to 40°F above the operating
header temperature. The upper over-
temperature limit switch is a manual reset device
and is not adjustable. It will shut the unit off if the
water temperature reaches 200°F. DO NOT
attempt to adjust its setpoint.
To adjust the lower over temperature switch limit
switc h:
1. Remove the wing nut from the top center of
the shell cap. Lift the cap off the shell.
2. The two over-temperature limit switches are
located at the top of the shell (see Fig. 4.6).
Do not adjust the upper switch it has been
factory preset. Adjust the lower switch
between 20° to 40°F higher than the
maximum header temperature the unit may
see.
3. Replace the shell cap and wing nut.