Beacon-Morris 11J11R00306-002 High Limit Switch (BM / BTU Series)

Product Overview

The Beacon-Morris 11J11R00306-002 High Limit Switch is a factory-original safety component designed for BM and BTU series unit heaters. This part plays a critical role in protecting your heating system by shutting down the burner if unsafe temperatures are detected, preventing overheating and equipment damage.

This updated switch replaces the older 3-prong design and is wired only to terminals 1 and 2 (terminal 3 is not used). It is compatible with a wide range of Beacon-Morris unit heater models and BTU sizes, making it a dependable choice for both garage heater repair and commercial HVAC maintenance.

Compatible Models: BMF, BMEF, BTU, BMSF, BMSB
Compatible Sizes (BTU): 100, 125, 150, 175, 200, 225, 250, 300, 400
Previous Part #: 21120
ID #: 604731

Features & Benefits

• OEM Replacement: Genuine Beacon-Morris high limit switch ensures compatibility and reliability.

• Safety Assurance: Prevents overheating by shutting down the system at unsafe temperatures.

• Updated Design: Replaces the older 3-prong switch for improved reliability.

• Wide Compatibility: Fits multiple BM and BTU series models across various BTU capacities.

• Durable Construction: Built for long-lasting performance in demanding HVAC environments.

Specifications

• Part Number: 11J11R00306-002

• Alternate Part Numbers: 203675, T-O-D 60T23, A1934 F170-40F

• Previous Part Number: 21120

• Compatible Models: BMF, BMEF, BTU, BMSF, BMSB

• BTU Ranges Supported: 100 – 400

• ID #: 604731

• Design Update: 2-terminal wiring (do not use terminal 3)

Installation Tips

• Always disconnect power before servicing unit heaters.

• Wire only to terminals 1 and 2; do not connect terminal 3.

• Verify compatibility with your unit heater model and BTU rating before installation.

• Inspect wiring and connections for wear before replacing the switch.

• For safety and compliance, professional installation by an HVAC technician is recommended.

FAQs

Q: What does a high limit switch do in a unit heater?
It protects the unit by shutting off the burner if the system temperature exceeds safe limits.

Q: Can this replace the older 3-prong high limit switch?
Yes, this updated version replaces the older 3-prong design. Use only terminals 1 and 2.

Q: Which Beacon-Morris models is this part compatible with?
It works with BMF, BMEF, BTU, BMSF, and BMSB series heaters.

Q: What BTU sizes does this switch support?
It is compatible with sizes from 100,000 to 400,000 BTU.

Q: Do I need a technician to install this part?
Professional installation is recommended to ensure proper function and safety.