Changing The Readout Between Fahrenheit And Celsius; Stack Guard Sensor Operation - Watts AERCO CFR 1500 Operation And Service Manual

SECTION 4 INITIAL START-UP
Figure 4-8: Manual Reset Over-Temperature Limit Switch

4.5.3 Changing the Readout Between Fahrenheit and Celsius

Perform the following steps to change the temperature reading between Fahrenheit or Celsius.
1. Press and hold both the Increase and Decrease arrows at the same time for about 4 seconds. The
display shows the temperature in Celsius and °F changes to °C.
2. To change the display back to Fahrenheit, repeat step 1.
Figure 4-9: Changing the Display to Celsius

4.6 Stack Guard Sensor Operation

The CFR's Stack Guard sensor is field-installed in the factory-provided vent starter section. The Edge
controller ensures the Stack Guard temperature stays above the Stack Guard Low Limit to prevent
condensation. When the Stack Guard temperature is below the Stack Guard Low Limit plus a user-
defined delta, the boiler firing rate is increased incrementally. If the Stack Guard temperature remains
below the Stack Guard Low Limit within a user-defined Exhaust Fault Time, the unit goes to "Low Stack
Temp Shutdown" and will restart after the outlet water temperature drops to 10°F below the
application setpoint.
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