Burner does not ignite, furnace locks out shortly after start attempt

Safety first: Turn off the main gas cock to the Hoval furnace and isolate electrical power at the service switch or breaker before opening any panels. Allow the combustion chamber to cool.

• Check gas supply: Verify that the external gas shut-off valve is open and that there is adequate gas pressure (compare to the rating plate and Hoval installation manual). If there is no gas, contact your gas supplier.
• Inspect the ionisation electrode: Remove the burner access panel. Locate the ionisation electrode on the Hoval burner assembly. Check for cracks in the ceramic, bent rod, or heavy soot. Clean the rod gently with fine emery cloth and wipe with a clean dry cloth. Reinstall with correct gap and position as per Hoval service data.
• Clean burner and injector: Remove the burner head and visually inspect the gas injector/nozzle for dirt or debris. Clean with a soft brush and compressed air (do not enlarge the orifice). Refit securely.
• Check ignition transformer and leads: Inspect the ignition transformer and high-voltage leads for burn marks, loose connections, or damaged insulation. Reseat all push-on connectors firmly. Replace damaged leads or transformer.
• Reset the control: Restore power and gas, then press the burner lockout/reset button on the Hoval control module (or front panel) once. Observe ignition. If lockout repeats, stop and contact a qualified Hoval technician.

Do not repeatedly reset a locking-out burner without finding the cause; unburned gas can accumulate and create an explosion hazard.