Boiler shows E1 and will not fire; may attempt ignition and shut down

Safety first: Turn off power and close the gas shutoff valve before working on the gas train or burner. If you smell gas, evacuate and call the gas utility.

Steps:

• Verify gas supply: Confirm the manual gas shutoff valve to the Peerless boiler gas valve is fully open. Check that other gas appliances in the home are working.
• Inspect burner area: Remove the burner access panel. Look for soot, rust flakes, or debris blocking the burner orifices. Clean gently with a soft brush and vacuum.
• Check ignition electrode: Inspect the spark electrode assembly for cracks, heavy buildup, or misalignment. The tip should be clean and positioned per Peerless specs (usually a few millimeters from the burner surface).
• Check flame sensor: On many Peerless boilers the flame rod is combined with the igniter. Clean the rod with fine emery cloth to remove oxidation.
• Inspect ignition cable: Ensure the high-voltage cable from the ignition transformer/ignition module to the electrode is not cracked or loose.
• Reset and test: Restore gas and power, then reset the boiler. If E1 returns, a technician should test gas pressure, ignition voltage, and replace the ignition/flame sensor assembly or gas valve as needed.