Boiler shows E1 and will not ignite, fan may start then stop

Safety first: Turn off power and close the manual gas shutoff valve before servicing. Allow the boiler to cool.

• Step 1 – Check gas supply: Confirm that the external gas shutoff valve to the Rheem boiler is fully open. Verify that other gas appliances in the home operate normally. If there is no gas to any appliance, contact your gas supplier.
• Step 2 – Inspect ignition and flame sensor: Remove the burner access cover. Locate the ignition electrode and flame sensor (often a combined assembly). Check for soot, oxidation, or cracks. Clean the flame sensor rod gently with fine emery cloth or a Scotch-Brite pad until shiny. Do not sand the ceramic insulator.
• Step 3 – Check electrode gap and position: Verify that the ignition electrode tip is positioned per the Rheem service manual (typically a few millimeters above the burner surface and in the flame path). Adjust carefully if bent.
• Step 4 – Restore gas and test: Open the gas valve, restore power, and attempt a restart. Observe through the sight glass: the igniter should spark and the burner should light smoothly. If you see sparking but no flame, suspect gas supply or gas valve issues.
• Step 5 – Gas valve and PCB checks: If there is confirmed gas supply and proper ignition spark but no flame, the gas valve coil or the ignition control circuit on the main PCB may be faulty. These components should be tested and replaced by a qualified technician using manometers and electrical tests.

Warning: Never attempt to adjust internal gas valve settings or burner orifices without proper training and instruments. Incorrect adjustments can lead to carbon monoxide production or explosion risk.