Furnace shows safety chain open, safety thermostat or limit circuit not closed

Safety: Identify and correct the cause of overheating before resetting any safety device.

• Check manual reset stats: Locate any manual reset safety thermostats on the Baxi appliance (often on the heat exchanger or flue hood). Once cooled, press the reset button if present.
• Inspect wiring: Trace the safety loop wiring for breaks, loose connectors, or signs of overheating.
• Investigate overheating: Verify pump operation, system pressure, and that all valves are open to ensure adequate flow.
• Replace faulty stat: If a thermostat will not reset or is open-circuit at normal temperature, replace it.