Siemens Combustion control unit LME11.330C2

This combustion control unit from Siemens is used for start-up and monitoring of 1-stage gas burners with intermittent operation. It operates with supply voltage 230 V AC and monitors the flame via an ionization electrode. The unit provides a pre-purge time of 30 s, a pre-ignition time of 2 s, and a safety time of 3 s; it has a waiting time of 2.5 s and an air pressure switch setting time of 65 s. It is rated for gas burners with capacity up to 120 kW.

Replacement of this kind of control unit must match the exact series and type designation, supply voltage, and programmed safety times (pre-purge, ignition, flame proving) of the original. The flame detection method — ionization, UV, or IR — must correspond to the installed detector, and the base or plug pattern must fit the existing chassis. Controls of this type are not interchangeable across series, even within the same brand; a mismatch in safety times creates a hazard. Before ordering, verify the coding on the existing unit against the manufacturer’s designation to ensure identical sequence timing and electrical ratings.