Troubleshooting OSG Over Speed Governor Fault in Acorn 180 Stairlifts F7 Code
The Acorn 180 Stairlift is renowned for its reliability and functionality in providing mobility solutions within homes. However, like any mechanical device, it can encounter faults that may cause inconvenience or concern to users. One such issue is the OSG (Over Speed Governor) fault. This blog post will guide you through understanding and possibly resolving this fault.
What is an OSG (Over Speed Governor)?
The Over Speed Governor (OSG) is a critical safety component in the Acorn 180 Stairlift. Its primary function is to detect if the stairlift is moving too quickly and, in such cases, activate the brake mechanism to prevent accidents or injury.

Understanding the OSG Over Speed Governor Fault
An OSG fault typically indicates that the stairlift believes it is moving faster than its designated safe speed. When this fault occurs, the lift will usually stop operation to protect the user. The fault may arise from various issues such as sensor malfunctions, wiring problems, or even issues in the mechanical components of the stairlift.
Common Causes of OSG Faults
- Faulty Sensors: The sensors that monitor the speed of the stairlift could be damaged or malfunctioning.
- Wiring Issues: Loose or damaged wires can disrupt the communication between the OSG and the control unit.
- Mechanical Problems: Wear and tear in the stairlift’s mechanical parts, such as gears and motors, might cause the OSG to misinterpret speed data.
Steps to Troubleshoot and Resolve OSG Faults
1. Inspect for Obstructions
- Ensure there are no physical obstructions on the stairlift track. Objects on the track can cause irregular movement triggering the OSG.
2. Reset the Stairlift
- Turn off the stairlift and wait for about 30 seconds before turning it on again. Sometimes, a reset can clear minor faults.
3. Check the Sensors
- Inspect the speed sensors for any visible damage. Ensure they are clean and correctly positioned.
4. Examine the Wiring
- Carefully inspect the wiring leading to and from the OSG. Look for loose or damaged wires and secure or replace them as necessary.
5. Clean Moving Parts
- Regular Service and Cleaning of the stairlift’s moving parts can prevent wear and tear that may cause the OSG to trigger incorrectly.
6. Professional Help
- If the fault persists, contacting a professional stairlift engineer is recommended. They have the tools and expertise to diagnose and repair more complex issues.
Final Thoughts
Addressing OSG faults in the Acorn 180 Stairlift promptly ensures continued safe and reliable operation of the stairlift. While some issues can be resolved with basic troubleshooting, more severe problems require professional attention to maintain the safety and longevity of the equipment.
Regular maintenance and inspections can prevent many faults from occurring, so always follow the manufacturer’s guidelines for service schedules. Remember, safety first—never hesitate to seek professional help when in doubt.