MC2: 10/03/12 Page
43
of
90
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
•
Ph: 800-526-0288
GF-115-H
OMM-0083_0B
Modulex MLX Series Gas Fired Boiler System
Operation and Maintenance Manual
Chap 8: Safety
Device Testing
8.4 LOW WATER LEVEL FAULT TEST
There are two ways in which to test the low water level fault. Method 1 requires draining the unit, while
the other involves pressing a “test” button while the unit is operating to check the sensor operation. To
simulate a low water level fault, proceed as follows:
NOTE
This sensor is located on the CSD-1 header
Low Water Level Fault Test (Method 1)
1. Set the
ON/OFF
switch to the
ON
position to start the E8 controller, and then select the
GENERAL/SERVICE/CASCADE MANU menu, which will prevent the boiler from firing.
2. Close the water shut-off valves in the supply and return piping to the unit.
3. Slowly open the drain valve on the rear of the unit. If necessary the unit’s relief valve may be opened
to aid in draining.
4. Continue draining the unit until the amber “Low Water” LED on the low-water cut-off switch illuminates
(see Figure 8-2). The unit should shut off completely (the E8 controller will turn off).
5. Close the drain and pressure relief valve used in draining the unit.
6. Open the water shut-off valve in the return piping to the unit.
7. Open the water supply shut-off valve to the unit to refill.
8. After the unit is full, press the Reset button on the water level sensor to reset the cutoff switch.
9. Power is now restored to the unit. There will be no fault code displayed on the E8 controller.
Low Water Level Fault Test (Method 2)
1. Set the
ON/OFF
switch to the
ON
position to start the E8 controller, and then select the
GENERAL/SERVICE/CASCADE MANU menu, which will prevent the boiler from firing.
2. Press and hold the “TEST” button on the low water cut-off switch (Figure 8-2). The unit should shut
off completely (the E8 controller will turn off).
3. Release the “test” button, then press and release the “reset” button.
4. Power is now restored to the unit. There will be no fault code displayed on the E8 controller.
Figure 8-2: Low Water Cut-Off Switch and Controls
Reset Button
Test Button
Low Water LED (Amber)
Lock Out LED (Red)
