John Wood Commercial - 300-400K BTU - Manual (Page 44)

44
user settings & control system menus
temperatures menu
operating set point and differential adjustment
The Operating Set Point is adjustable from 90°F (42°C) to 180°F (82°C). The factory setting is 120°F (49°C). The Differential is
adjustable from 2° to 20°. The factory setting is 8°. These user settings are accessed from the Temperatures menu. The following
instructions will explain how to adjust these settings and navigate the control system menus.
When the water temperature sensed by the control system from the two (upper and lower) Temperature Probes reaches the Operating
Set Point the control system will end the heating cycle. A heating cycle will be activated again when the sensed water temperature
drops below the Operating Set Point minus the Differential setting.
note:
Lower Differential settings may cause excessive heating cycles (short-cycling) which can cause premature failure of
components such as the Hot Surface Igniter. Set the Differential at the highest setting which produces an acceptable hot water
supply. Set the Operating Set Point to the lowest setting which produces an acceptable hot water supply for most efficient use.
description/action display
From the Desktop screen, press the Operational button under
MENu. The "Main Menu" screen will be displayed.
Tank Temperature 120°F
Operating Set Point 120°F
Status: Standby
MENU HELP
MANUFACTURER / MODEL INFORMATION
The Main Menu is where all control system menus are listed,
see Table 12 on page 43 for a complete list and description
of control system menus. use the up and Down buttons to
view all control system menus from the Main Menu.
With Temperatures menu selected (highlighted in black) in
the Main Menu screen, press the Operational button under
“SELECT” to enter the Temperatures menu.
If the Temperatures menu is not selected use the up and Down
buttons to select this menu item.
Temperatures
Heater Status
Display Settings
Heater Information
Current Fault
SELECT BACK HELP
Main Menu
With the Operating Set Point selected in the Temperatures
menu, press the Operational button underneath “CHANgE” to
activate the adjustment mode for this menu item.
If Operating Set Point is not selected use the up and Down
buttons to select this menu item.
note:
Higher Temperature settings increase wear and
operating costs. Set the Operating Set Point to the lowest
setting which produces an acceptable hot water supply. This
will always provide the most energy efficient operation and
longer life.
Operating Set Point 120°F
Differential 8°F
Tank Temperature 120°F
Upper Temperature 122°F
Lower Temperature 118°F
(Heater Regulated to Tank)
Upper Probe Offset 0°F
CHANGE BACK HELP
Temperatures
With the adjustment mode for the Operating Set Point activated
the selection bar will change from a black fill to a black outline.
use the up and Down buttons to change the current setting.
Press the Operational button under "uPDATE" to save the
new setting. Press the Operational button under "CANCEL" to
discard changes and return to the previously saved setting.
note:
use this same procedure to change the Differential
setting and other adjustable user settings in the control system
menus.
Operating Set Point 140°F
Differential 8°F
Tank Temperature 120°F
Upper Temperature 122°F
Lower Temperature 118°F
(Heater Regulated to Tank)
Upper Probe Offset 0°F
UPDATE CANCEL
Temperatures