
Check the operation of the sensor by isolating the boiler from its system piping, and close the system
fill valve, and then crack the pressure relief valve. The pressure displayed should reflect declining
pressure. If it remains “fixed”, drain the boiler and replace the sensor, or dislodge any blocking debris
from the sensor inlet channel and reinsert.
8.1.4 DHW flow sensor
The DHW flow sensor ensures that there is adequate flow in the DHW system. The flow is displayed
in GPM as the default. A minimum of 0.5 GPM is required to activate the DHW heating.
Check the operation of the sensor by allowing domestic water to flow through the unit. On the
controller, go to
Status > Boiler Status
, and scroll down to view the
DHW Flow
. The display
should indicate a number greater than 0 (zero). Check the flow sensor for fouling or loose wiring. If
sensor is spinning freely and connected, replace the sensor.
8.1.5 Safety and Ignition Module (SIM+)
The SIM+ is a safety control, certified to conform to the UL 60730-5-5 and ANSI Z21.20-2014 •
CAN/CSA-C22.2 No. 60730-2-5-14 standards.
The module controls the boiler’s combustion fan, gas valve, sensors, safety and ignition functions
including:
Direct spark automatic ignition
Flame detection and current measurement
Supply water temperature sensing
Flue gas temperature sensing
Supply water maximum temperature shutdown
Flue gas maximum temperature shutdown
Low water cut-off.
The SIM+ continuously communicates with the boiler’s main controller reporting sensor readings
and status. The sensor readings and error status, if any are displayed on the boiler controller’s
screen.
8.1.5.1 Table showing LED operating status
Its two status LEDs indicate the operating status as shown in the table below.
105
8.1.4 DHW flow sensor
Summary of Contents for CX Series
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Page 114: ...Appendices Wiring diagrams Figure 48 Controller electrical diagram 114 Section Troubleshooting...
Page 115: ...Figure 49 Internal wiring diagram 115 Wiring diagrams...
Page 116: ...Figure 50 Sequence of Operation 116 Section Troubleshooting...