Siemens Electromechanical burner control LFL1.133

Siemens electromechanical burner control LFL1.133 (SKU LFL1.133) is a control box used for start-up and monitoring of medium to high power forced-draft burners firing gas, oil, or combined fuel. It operates with multi-stage or modulating burners in intermittent operation. The control is supplied at 230 V and has a safety time of 3 s, pre-purge time of 9 s, pre-ignition time of 3 s, post-purge time of 14.5 s, and a start-up sequence duration of 29 s. It monitors pressure switches and the flame detector, and sequences the ignition transformer, fuel valve, and fan.

Replacements for this type of control are selected by the exact series and type designation, supply voltage, safety and pre-purge times, flame detection method (ionisation, UV, or IR), and the base or plug pattern. Controls of this class are normally not interchangeable across series, even within the same brand; a mismatched safety time presents a safety hazard. Before ordering, compare the markings on the existing control and verify that all timing and detection parameters match the original. The control board in modern wall-hung boilers is matched to the specific boiler model and is not a drop-in substitute.