58
Water heater temperature regulation
Operating temperature (target)
The electronic control module senses water temperature in
the tank and regulates water heater ignition and firing rate to
achieve a target temperature. The target temperature can be
set between 60°F and 180°F.
High limit operations
The Shield water heater is equipped with a fixed automatic
reset high limit and an adjustable manual reset high limit.
The automatic reset high limit has a set point of 200°F and
the manual reset high limit has a maximum set point of
210°F.
When the outlet temperature exceeds 200°F, the automatic
high limit action occurs. The water heater shuts down until
the outlet water temperature cools below 190°F, and a 60
second timer has expired. If the outlet temperature continues
to increase, the manual reset high limit action will occur at
210°F.
Manual Reset High Limit (MRHL) test procedure
10
Operating information
Installation & Service Manual
1. With the unit powered ON, note the HEX OUTLET
temperature shown on the Main Screen.
2. Enter the Installer Menu by pressing the
►
button from
the Main Screen and then entering the installer password.
3. Navigate to the GENERAL submenu and select MRHL
SETPOINT from the menu options.
4. Adjust the MRHL SETPOINT value to a temperature
below the noted HEX OUTLET temperature from Step
1.
5. Press the
◄
button to save changes and return to the
Installer Menu.
6. Press the
◄
button to return to the Main Screen.
7. The water heater will lock out and display "OUTLET
MRHL".
8. Enter the Installer Menu by pressing the
►
button from
the Main Screen and then entering the installer password.
9. Navigate to the GENERAL submenu and select MRHL
SETPOINT from the menu options.
10. Adjust the MRHL SETPOINT value to the desired value
for normal operation.
11. Press the
◄
button to save changes and return to the
Installer Menu.
12. Press the
◄
button to return to the Main Screen.
13. Press the RESET button to clear the Manual Reset High
Limit lockout.
Adjustable control parameters
User adjustable parameters
The User Adjustable Parameters Menu can be accessed by
pressing the
◄
button from the Main Home Screen. Once
pressed, the tank temperature setpoint will be shown. Use the
▲/▼
to adjust the tank setpoint to the desired temperature.
Once the desired tank setpoint is selected, press the
◄
again to
save changes and exit the User Setpoint Menu.
Table 10A
User Adjustable Parameters
Parameter Description Factory
Default
Min
Max
TANK SETP
Tank / Hot
Water Setpoint
125°F
60°F
180°F
