Photo-Eye Sensor Alignment or Replacement: questions about the price

Arrangement varies by model: most pairs carry an indicator on each side, in differing colours for sender and receiver, though some older pairs light only the receiver, so check the maker's chart. A receiving light that is dark or flickering means the beam is not landing on it, so the pair needs aligning or something is in the way. Both lights dark means the pair has no power, which points to the wire or the terminals at the head unit. Steady lights on both sides mean a healthy system.

Length and route of the wire run

A damaged section near a sensor is a short repair. A fresh run from the motor to both sides of the doorway takes longer, more so where the wire is buried in a finished ceiling.

Type of kit

Some replacement kits contain only the two sensors with connectors, while others include brackets and a full length of wire. The kit that suits the opener and the state of the existing hardware is what is quoted.

Force and travel adjustment alongside

If the reversing turns out to involve a travel limit set long or a force setting made in summer, adjusting and re-testing those settings is included as a small extra step.