Understanding Liftmaster Error 5

When your Liftmaster garage door opener displays Error 5 (five flashes or blinks), it's indicating either an RPM (Revolutions Per Minute) sensor problem or issues with the chain/belt tension. This error affects the opener's ability to properly monitor and control the door's movement.

What Causes Error 5?

Several factors can trigger Error 5:

  • Chain or belt is too tight or too loose
  • Damaged or malfunctioning RPM sensor
  • Loose connections to the RPM sensor
  • Debris interfering with the sensor
  • Worn out drive components

How to Fix Error 5

Step 1: Check Chain/Belt Tension

First, inspect the drive system tension:

  1. Disconnect the opener from power
  2. Check the chain or belt for proper tension:
    • For chain drives: Should have about 1/4 inch of slack
    • For belt drives: Should have slight flex but remain taut
  3. Adjust tension if necessary using the adjustment bolt
  4. Ensure the chain/belt is properly aligned on sprockets/pulleys

Step 2: Inspect the RPM Sensor

Examine the RPM sensor components:

  1. Locate the RPM sensor (usually near the motor unit)
  2. Check for secure connections to the control board
  3. Look for any visible damage to the sensor
  4. Clean any dust or debris from the sensor area

Step 3: Test the System

After making adjustments:

  1. Restore power to the opener
  2. Run the door through several complete cycles
  3. Listen for unusual noises
  4. Observe the door's movement for smoothness

⚠️ Important Safety Note

Always disconnect power before working on your garage door opener. Improper chain/belt tension can cause premature wear or damage to your opener. If you're unsure about making adjustments, please consult a professional technician.

Signs of RPM Sensor Problems

Watch for these indicators of RPM sensor issues:

  • Door stops or reverses unexpectedly
  • Inconsistent door movement
  • Unusual noises during operation
  • Error 5 appears intermittently

Prevention Tips

To prevent Error 5 from recurring:

  • Schedule regular maintenance checks
  • Keep the drive system clean and properly lubricated
  • Check tension monthly
  • Address unusual noises promptly
  • Keep the RPM sensor area clean

When to Call a Professional

Seek professional help if:

  • You're uncomfortable making mechanical adjustments
  • The error persists after tension adjustments
  • You notice damaged components
  • The door's movement remains inconsistent