The furnace shows E22; the burner stops and restarts frequently.

Safety first: Surfaces may be hot. Isolate power before adjusting internal components.

• Open radiators: Ensure that enough radiators or heating circuits are open to dissipate the furnace output. Avoid closing all TRVs in the property.
• Check pump settings: On models with adjustable pump speed, set the pump to a higher speed to increase flow.
• Hydraulic balancing: Have a technician balance the system to ensure even flow through all circuits.
• Adjust maximum output: In the installer menu, reduce the maximum central heating output to better match the system load.
• Monitor operation: After adjustments, observe whether E22 and short cycling are reduced.