Siemens LMO14 / LMO24 / LMO44 Oil Burner Controllers

Siemens Burner Controllers LMO14 / LMO24 / LMO44 Series

Siemens LMO14 / LMO24 / LMO44 Series are microcontroller-based oil burner controls developed for automatic burner startup, ignition sequencing, flame supervision, and safe operation of forced-draft oil burners in intermittent mode.

The controllers use digital program sequencing to coordinate burner operation and monitor flame signals. Depending on the model, they support single-stage or two-stage fuel valve control, with safety lockout and multicolor LED status diagnostics.

Key Features

• Automatic startup and ignition sequencing for forced-draft oil burners
• Single-stage control with LMO14 and two-stage control with LMO24 / LMO44
• Oil throughput below 30 kg/h, including applications above 30 kg/h on selected versions
• Yellow-flame detection with QRB1, QRB3 or QRB4
• Blue-flame detection with QRC1
• Integrated undervoltage monitoring
• Electrical remote reset functionality
• Oil preheater monitoring and bridging contact
• Accurate digital burner program sequencing
• Controlled intermittent operation after 24 hours of continuous operation
• Restart limitation for burner safety
• Multicolor LED operating and fault indication
• Diagnostic support through OCI400 and ACS410 software

LMO14 / LMO24 / LMO44 Series Comparison

Compatible Flame Detectors

• QRB1 / QRB3: Photoresistive detectors for yellow-burning oil flames
• QRB4: Yellow-flame detector
• QRC1: Blue-flame detector

Typical Applications

• Industrial oil-fired boilers
• Forced-draft oil burner systems
• Steam generators
• Industrial heating equipment
• Stationary direct-fired air heaters on supported models

Product Selection Guidelines

Verify the complete model reference, supply voltage, burner stage configuration, oil throughput, flame detector type, prepurge time (t1), ignition safety time (TSA), and existing electrical wiring before ordering or replacing a controller.

Important: Installation, commissioning, and replacement must be performed by qualified personnel according to Siemens technical documentation. When replacing an LOA controller, check any required changes to the ignition transformer wiring and other safety-related connections.

Technical Specifications - Siemens LMO14 / LMO24 / LMO44 Series

Model Reference and Control Timing

Timing Note: t1 refers to minimum prepurge time and TSA to maximum ignition safety time. Corresponding purge times (t1') are 16 s, 6 s, or 26 s depending on model. Values are based on Siemens CC1N7130en and must be verified before installation or replacement.