Burner does not start, control locks out shortly after call for heat

Safety first: Turn off the main power switch to the furnace and close the fuel shutoff valve (gas cock or oil service valve). Wait several minutes before working near the burner. If you smell gas, do not attempt repair—ventilate the area and contact a professional immediately.

Step-by-step checks:

• Verify fuel supply: Ensure the main gas valve or oil service valve to the Weishaupt burner is fully open. Check that the fuel tank is not empty and that any external safety shutoff valves are not tripped.
• Reset burner control: Locate the Weishaupt burner control box (e.g., W-FM 25/50/100 or WCM controller). Press the reset button once only. If the burner starts and runs normally, monitor for recurrence. Repeated lockouts indicate a real fault.
• Inspect ignition components: Remove the burner cover. Check the ignition transformer/ignition unit and high-voltage leads for damage or loose connections. Inspect ignition electrodes at the burner head for cracks, carbon buildup, or incorrect gap. Clean with fine emery cloth and adjust to the manufacturer’s specified gap and position.
• Check flame sensor: Inspect the ionization electrode or UV flame sensor (depending on model). Clean the sensor rod or UV tube window with a soft cloth. Ensure the sensor wiring is firmly connected to the control module.
• Check gas/oil valves: Confirm that the Weishaupt gas valve train or oil solenoid valves click or energize during start-up. If there is no sound or the valve coil is cold, test for power at the valve terminals (qualified personnel only). Replace the faulty valve coil or complete valve assembly if defective.

When to call a technician: If E01 recurs after basic checks, or if you are not trained to work on combustion systems, contact a certified Weishaupt service technician for combustion analysis, valve testing, and control diagnostics.