42
PN 240012875 REV. D [03/15/2022]
LOW WATER CUTOFF
Low Water Cut Off - Heating Only and Combi Boilers
These guidelines are supplied when necessary to install
an additional Low Water Cut Off (LWCO), for sensing a
low water level condition in a boiler, as required by the
Authority Having Jurisdiction.
Follow LWCO manufacturer installation instructions for
type of LWCO selected in addition to these instructions.
LWCO shall be 120V/60HZ control and dry contacts sized
for load being connected. Wire control to boiler. See Figure
below.
Connect LWCO device to the system ground. Ground Boiler
in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements,
with the National Electrical Code (NEC) or Canadian
Electrical Code CEC.
• Locate LWCO sensing device in the supply
piping, above the minimum height of boiler.
See Figure page 42, Piping Diagram.
• Position control in piping above boiler to assure
proper boiler protection.
• For proper operation, sensing element of the LWCO
control shall be positioned in the tee to sense the
main water stream. Maintain minimum 1/4” spacing
from pipe walls. Element shall NOT contact the rear,
or side walls of the tee. See Figure page 43.
• Install an air vent using a tee to avoid nuisance
shutdowns.
• Apply small amount of pipe sealant to threaded
connections.
• Arrange piping to prevent water dripping onto boiler.
• DO NOT install water shutoff valve between boiler
and LWCO sensing device.
LWCO WIRING DIAGRAM
Low Water Cutoff (LWCO)
Electrical Conduit
J-Box
120 V/60 HZ
Conduit or Power
Supply cord
(Polarized)
L
1
N
G
GND
L
1
N
GND
BLK
WHT
120 V/60 HZ Socket
(Polarized) 120 V/60 HZ
Cord Set From Boiler
N.O
Summary of Contents for 100F
Page 33: ...33 PN 240012875 REV D 03 15 2022 MODEL 75 100 HEAT ONLY 75 100 HEAT ONLY WIRING DIAGRAM ...
Page 34: ...34 PN 240012875 REV D 03 15 2022 MODEL 125 HEAT ONLY 125 HEAT ONLY WIRING DIAGRAM ...
Page 35: ...35 PN 240012875 REV D 03 15 2022 MODEL 165 HEAT ONLY 165 HEAT ONLY WIRING DIAGRAM ...
Page 36: ...36 PN 240012875 REV D 03 15 2022 115 COMBI WIRING DIAGRAM MODEL 115 COMBI ...
Page 37: ...37 PN 240012875 REV D 03 15 2022 MODEL 150 COMBI 150 COMBI WIRING DIAGRAM ...
Page 38: ...38 PN 240012875 REV D 03 15 2022 MODEL 205 COMBI 205 COMBI WIRING DIAGRAM ...
Page 44: ...44 PN 240012875 REV D 03 15 2022 LOW WATER CUTOFF LOW WATER CUTOFF DETAIL NO NO YES ...
Page 49: ...49 PN 240012875 REV D 03 15 2022 3 FAULT SOLUTION SECTIONS ...
