AERCO BMK 2000DF - Manual (Page 81)

Benchmark 1500DF - 2000DF Boilers
CHAPTER 6 – SAFETY DEVICE TESTING
OMM-0098_0A AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 Page 81 of 196
GF-144 Ph.: 800-526-0288 04/01/2014
Low Water Level Fault – Continued
7. Close the drain and pressure relief valve used in draining the unit.
8. Open the water shut-off valve in the return piping to the unit.
9. Open the water supply shut-off valve to the unit to refill.
10. After the shell is full, press the LOW WATER LEVEL RESET button to reset the low
water cutoff.
11. Press the CLEAR button to reset the FAULT LED and clear the displayed error
message.
12. Set the ON/OFF switch to the ON position. The unit is now ready for operation.
6.5 WATER TEMPERATURE FAULT TEST
A high water temperature fault is simulated by adjusting the automatic over-temperature switch.
This switch is accessible from the front of the unit as shown in Figure 6-2.
Water Temperature Fault Test
1. Start the unit in the normal operating mode. Allow the unit to stabilize at its setpoint.
2. Lower the adjustable over-temperature switch setting to match the displayed OUTLET
TEMPERATURE.
3. Once the adjustable over-temperature switch setting is approximately at, or just below,
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
4. Reset the adjustable over-temperature switch to its original setting.
5. The unit should start once the adjustable temperature limit switch setting is above the
actual outlet water temperature.
6. Once the adjustable over-temperature switch setting is approximately at, or just below,
the actual outlet water temperature, the unit should shut down. The FAULT indicator
should start flashing and a HIGH WATER TEMP SWITCH OPEN fault message should
be displayed. It should not be possible to restart the unit.
7. Reset the adjustable over-temperature switch to its original setting.
8. The unit should start once the adjustable temperature limit switch setting is above the
actual outlet water temperature.