Hands-On Learning, Powering America Forward

Diagnosing and Replacing Fan and Limit Combination Switch 

 

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CONTENT TYPE

VR, ILV, Interactive Modules

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DURATION

2 Hours

Target Audience icon

TARGET AUDIENCE

Technician

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COURSE DELIVERY

VR and Web-based

Credits icon

Credits : 0.2

Icons representing a four-step workflow: Learn, Assess, Evaluate, and Implement

 

About the Course:

This Diagnosing and Replacing Fan and Limit Combination Switch microcredential trains HVAC technicians to safely diagnose, remove, and replace faulty fan and limit combination switches in furnace systems. Learners practice real-world troubleshooting steps including safe power shutdown, wire disconnection, resistance testing using a multimeter, component removal with hand tools, and secure installation of a compatible replacement switch. The course emphasizes electrical safety, accurate diagnosis using ohms testing, proper wiring configuration, and verification procedures to ensure reliable blower operation and furnace temperature protection. Technicians can further expand their skills with our Hands-On HVAC Technician Training program.

Learning Objectives:

  • Identify symptoms of a faulty fan and limit combination switch, including open circuit readings 
  • Safely power down the furnace using proper disconnect procedures 
  • Disconnect wiring and remove conduit safely before servicing 
  • Use a multimeter set to ohms to test fan and limit switch continuity 
  • Interpret OL (open line) readings to confirm switch failure 
  • Remove faulty fan and limit components using correct tools and safety protocols 
  • Install and secure a compatible replacement switch 
  • Reconnect wiring according to proper configuration 
  • Restore power and verify correct fan and limit operation through testing 

 

Course delivered via LMS and requires an Oculus VR headset for hands-on VR simulations.

 

HVAC technician diagnosing fan and limit combination switch in furnace system

 

Workforce Development

HVAC technician testing fan and limit combination switch continuity with a multimeter

At ImmerseLearn, we equip HVAC technicians with hands-on, job-ready skills for diagnosing and servicing furnace control components. This microcredential strengthens electrical troubleshooting accuracy, safe servicing procedures, and component replacement precision through immersive VR practice. For learners new to HVAC concepts, a structured HVAC training option is available to help build foundational understanding.

How this course strengthens workforce skills:

Fan and Limit Diagnostics −
Learners begin by turning off power to the furnace at the disconnect and safely removing all connected wires along with the main wire conduit. Using a multimeter set to ohms, they test the fan switch and then the limit switch terminals. When both readings display OL (open line), technicians confirm the fan and limit combination switch is faulty, ensuring accurate diagnosis before replacement.
Safe Removal and Component Replacement +
Technicians use a nut driver to loosen and remove the mounting nuts securing the faulty fan and limit combination switch, then carefully remove it from the furnace. A compatible new switch is positioned in place, secured and tightened, the main wire conduit is reattached, and all wires are properly reconnected according to the correct configuration.
Restoration and Verification +
After completing installation, technicians restore furnace power. System operation is verified by observing proper blower engagement and confirming safe temperature control functionality.

By completing this microcredential, HVAC technicians build the confidence and technical skills required to diagnose fan and limit switch failures, replace components safely, and restore reliable furnace system performance.