Boiler locks out shortly after start, red lockout lamp on burner control, no flame established.

Safety first: Turn off the boiler at the main switch and close the gas shut-off valve. Allow the appliance to cool. Only qualified personnel should work on gas components.

• Reset and observe: Press the burner control reset button once. Observe through the sight glass: check if you see sparking and hear the ignition transformer clicking.
• Check gas supply: Ensure the external gas cock is open and that any Weishaupt gas train manual shut-off valves are in the open position. Verify gas pressure on the inlet gauge if available.
• Inspect ionisation/ignition electrodes: Remove the burner cover. Visually inspect the ignition and ionisation electrodes for cracks, heavy deposits, or damage. Clean gently with fine emery cloth and check the ceramic for hairline cracks.
• Verify electrode gap and position: Compare electrode position and gap with the Weishaupt burner manual (typical gap 3–4 mm, but follow model-specific data). Adjust carefully so the spark is in the main gas stream.
• Check ignition transformer and cables: Inspect ignition cables for burn marks or loose connections at the ignition transformer and electrode. Tighten connections. If no spark is visible and 230 V is present at the transformer, the transformer may be defective and should be replaced.
• Test flame signal: After cleaning and adjustment, restart the boiler. If the flame lights but the burner still locks out after a few seconds, the ionisation electrode or flame monitoring circuit may be faulty and should be replaced or tested by a technician.

When to call a professional: If there is no gas pressure, if the gas valve does not open, or if you are not certified to work on gas appliances, contact an authorised Weishaupt service technician.