Belimo EFB24 Actuator 30067439-890 two of these modulating damper

two of these modulating damper actuators can be mounted in tandem to double the effective torque output to 280 lb-in on a single shaft

As a direct OEM replacement HVAC part

the assembly survives the thermal stress typical of frequent ignition cycles in high-efficiency systems

or the burner failing to ignite due to the control circuit not closing

Belimo EFB24 Actuator 30067439-890 two of these modulating damperThe Belimo EFB24 is a heavy duty spring return actuator engineered for on off control in high torque HVAC applications. Delivering 270 in lb of torque, this unit is designed to automate large control dampers and specialized valve assemblies. Operating on 24VAC DC, the EFB24 utilizes a mechanical spring return system to ensure a defined fail safe position during power loss, providing critical protection for air handling units and industrial ventilation