ECR International CHB Application Manual page 34

LWCO Wiring Diagram
Key
16
Modulating fan
32 Heating circulating pump
42 DHW temperature sensor (see kit)
44 Gas valve
47 Modulation Regulator (24V)
72
Room thermostat (field sourced)
81 Ignition/detection electrode
114
Water pressure switch
138 External probe (not fitted)
155 Hot water tank temperature probe (field sourced)
278 Double sensor (Safety + Heating)
297 Air pressure transducer
370 Low Water Cutoff (LWCO) (field sourced)
OPTIONAL EQUIPMENT - LOW WATER CUTOFF
138 - Optional Outdoor Sensor
155 - Optional Indirect Tank Sensor
370 - Field Source LWCO
*IMPORTANT:
• Before connecting the room thermostat, remove
jumper on terminal block. (Key 72)
• Before connecting optional Indirect Tank Sensor,
remove two resistors, (Key 155)
• Before connecting the Low Water Cutoff, remove the
jumper on terminal block. (Key 370)
34
NOTICE