Furnace attempts to start but shuts down with E2 on display

Safety first: Isolate power and close the gas valve before removing covers. Combustion components must only be serviced by qualified personnel.

• Check gas supply stability: If other gas appliances fluctuate or go out, contact the gas supplier to check inlet pressure.
• Inspect burner: Remove and visually inspect the premix burner for corrosion, debris, or soot. Clean according to Remeha guidelines using a soft brush and vacuum. Do not use sharp tools that may damage the burner surface.
• Clean venturi and air intake: Check the venturi and air intake for dust, insects, or obstructions. Clean gently and ensure the air intake grille is not blocked.
• Check ionisation electrode: Clean and reposition the ionisation electrode so it is correctly in the flame path. Replace if the ceramic is cracked or the rod is worn.
• Technician checks: If E2 persists, a technician should measure gas valve modulation, combustion quality (CO₂/O₂), and replace the gas valve or control PCB if necessary.