5-5
TROUBLESHOOTING
SL 35-199, SL 45-260 MODULATING GAS BOILERS
5.2.7 Optional Low Water Cut Off
The boiler can be ordered with a UL 353 certified probe-type low water cut off
(LWCO) device factory installed or a Field Installed retrofit kit (boiler model
specific) can be ordered from your local wholesaler.
The LWCO option has a test and reset button located above and to the left of the
controller. The LWCO module will automatically reset after a power interruption
and the boiler will continue to operate as long as the boiler was not in a low water
condition prior to the power outage. The module has a red LED light near the top
of the clear plastic casing. If the red LED is not illuminated, either the module
has detected a low water condition and shut off the boiler or the module has no
power.
TESTING THE LWCO MODULE:
To test the LWCO module, press and hold the TEST button for 3 seconds. The
LWCO module will shut down the boiler, display a RED bar at the bottom of the
touch screen displaying Low Water Cut Off and the red LED on the module will
turn off.
RESETING THE LWCO MODULE:
Before resetting the LWCO module, ensure that the system if fully charged with
water and that all the air has been bled.
To reset the LWCO module, press the reset button. The red LED will illuminate
again indicating that the low water condition is not currently present. The boiler
controller will continue to be in a lock out mode for 60 minutes. The controller
can be manually reset by entering Diagnostics, Advanced Diagnostics menu and
pressing Clear Errors.
CLEANING THE LWCO PROBE:
If the probe should become dirty, the Red LED will flash every half second
indicating that the probe should be cleaned. The LWCO probe is located in the
supply pipe on the left side of the heat exchanger as seen in the photo. Before
removing the probe for cleaning, ensure you have turned off the gas supply and
the power to the boiler. Isolate the boiler from the heating system and remove
the water pressure. Carefully disconnect the Yellow and Green wires from the
probe. Remove the probe and clean with water and a cloth. Do not use sand
cloth to clean the probe. In some cases the probe should be replaced to restore
normal operation. Ensure the heating system water quality is clean and clear to
prevent nuisances Low Water Cut Off tripping.
LWCO Module
Test and Reset Buttons
Summary of Contents for SL 35-199
Page 71: ...SERVICE RECORD DATE LICENSED CONTRACTOR DESCRIPTION OF WORK DONE...
Page 72: ...NOTES...
Page 73: ...NOTES...
