Boiler shows E2 and locks out; no ignition

Safety: Turn off gas and power. Only a qualified gas technician should work on gas valves and ignition systems.

• 1. Check gas supply: Ensure the gas cock to the Buderus boiler is open and that other gas appliances in the property work.
• 2. Reset once: Perform a single reset. If E2 returns, do not continue resetting.
• 3. Inspect ignition electrode: Remove the burner cover and check the electrode for cracks, heavy deposits, or incorrect gap. Clean or replace as needed.
• 4. Check ignition cable: Inspect for burns, cuts, or loose connections at both the electrode and control board.
• 5. Gas valve and pressure: A technician should verify that the gas valve opens and that correct inlet pressure is present during ignition attempts.
• 6. Control board: If all mechanical and gas components are good, the control board may not be generating ignition voltage and may need replacement.