Troubleshooting Guide for Rheem Criterion II Gas Furnace
1. Why is the Main Burner Flame Lighting Intermittently?
The intermittent main burner flame lighting in a Rheem Criterion II gas furnace can be caused by several issues, including:
Flame Sensor Issues:
– The flame sensor may be dirty or damaged, preventing it from properly detecting the flame. Clean the flame sensor using pure steel wool and check the connections for any damage or loose wiring.
Igniter Problems:
– If the igniter is not functioning correctly, it may not provide enough heat to sustain the flame. Check if the igniter is glowing as expected, and replace it if necessary.
Gas Valve Issues:
– The gas valve might be malfunctioning, preventing consistent gas flow. Check for any blockages or issues with the gas manifold and ensure the gas pressure is within the specified range.
Pressure Switch Problems:
– The pressure switch could be operating at the edge of failure, preventing the system from detecting the flame correctly. Check the pressure switch operation using a manometer.
Control Board Issues:
– The control board might be faulty, preventing the proper ignition sequence. Check for any error codes on the IFC panel and ensure the board is functioning correctly.
2. Why is the Furnace Failing to Enter the Ignition Sequence?
The ignition sequence in a Rheem Criterion II gas furnace involves the thermostat calling for heat, the inducer fan turning on, the igniter glowing, and the gas valve opening to ignite the burners. Failure to enter this sequence can be caused by:
Control Board Issues:
– The control board might not be sending the proper signals to the igniter or gas valve. Check for any error codes on the IFC panel.
Pressure Switch Issues:
– The pressure switch might not be closing correctly, preventing the gas valve from opening. Verify the pressure switch operation using a manometer.
Igniter Problems:
– The igniter might not be glowing as expected. Check if the igniter is new and functioning correctly.
Gas Valve Issues:
– The gas valve could be malfunctioning or blocked. Ensure the gas manifold is clear and the gas pressure is correct.
3. Why is the IFC Panel Showing a Solid Green LED Light?
The solid green LED light on the IFC (Integrated Furnace Control) panel of a Rheem Criterion II gas furnace typically indicates that the system is in a normal operating state. However, it can also indicate a lack of flame detection, which could mean the flame sensor is not detecting the flame correctly.
Troubleshooting Steps:
– Check the flame sensor to ensure it is clean and properly connected. Verify the DC current from the flame sensor to the IFC board.
– Inspect the igniter and burners to ensure they are functioning correctly. If the burners are not igniting, check the gas valve and manifold for any blockages.
– Verify the pressure switch is operating correctly. If the pressure switch is not closing, it could prevent the system from detecting the flame.
