Furnace shows E15, burner stops, and the fan may continue to run for a purge period.

Safety: Isolate gas and power before opening the burner compartment.

• Check gas supply stability: If other gas appliances flicker or go out, contact your gas supplier to check for pressure issues.
• Clean burner head: Remove the burner from the Viadrus furnace according to the manual. Clean the burner head and ports with a soft brush and compressed air. Remove soot and rust.
• Inspect ionization electrode: Clean the flame sensing electrode as described for E02. Ensure the cable is secure and not touching hot surfaces.
• Test gas valve: A technician can monitor coil voltage and measure gas pressure during operation to identify intermittent valve failure. Replace the gas valve assembly if confirmed faulty.