Chimney Flap

Chimney Flap: In heating systems that operate on the stop-start principle, the chimney performs the traction function for effective heat transfer.



However, when the burner is on standby, the boiler starts to cool down through the chimney as the chimney heats up and losses occur.



During burner standby, that is, when the boiler water is set, the thermostat drops to the lower value faster. When the burner is not working, the disk inside the flap rotates 90° on its own axis, thanks to the spring inside the servo motor, and closes the chimney path.



Since the burner inserts the combustion air inlet covers during standby (except for old burners), the cooling of the boiler, and therefore the boiler water, is prevented by the chimney draft. When the boiler water temperature drops to the set value, the thermostat closes the electrical circuit for the burner to operate.



Since the electrical connection of the motor-actuated valve is connected in series with the thermostat, the servo motor of the valve operates first; After the disk inside the flap opens 80% of the chimney path, the final switch allows the burner to operate.

As long as the electrical connection between the burner and the flap is made in series, it is extremely safe; That is, the burner will not work unless the flap is opened.