Boiler displays EA and locks out, often with fan running but no ignition

Safety first: Turn off power and gas. Allow the boiler to cool before removing covers.

• Step 1 – Inspect vent and intake: Check the Rheem boiler’s vent and air intake for obstructions, sagging, or improper slope. Clear any debris or ice from terminations.
• Step 2 – Check pressure tubing: Locate the air pressure switch and its silicone tubes. Ensure tubes are not cracked, kinked, or filled with condensate. Replace damaged tubing and clear any moisture.
• Step 3 – Test pressure switch: With power off, disconnect the wires from the pressure switch and test continuity while gently applying suction to the appropriate port. The switch should close reliably. Replace if it fails to operate per Rheem specifications.
• Step 4 – Verify fan operation: Ensure the combustion fan starts and reaches full speed. A weak fan may not create enough pressure to close the switch. Replace the fan if it is noisy, slow, or fails to start.
• Step 5 – Reset and test: After corrections, restore power and gas, then reset the boiler. Monitor operation to confirm EA does not return.

Warning: Never bypass the air pressure switch to keep the boiler running. This can allow operation with a blocked flue, creating a severe carbon monoxide hazard.