What is the major cause of BJ thermostat failure?

The major cause of BJ thermostat failure is related to the physical interaction with the adjustment mechanism, specifically the adjustment screw. If the technician or user does not push in hard on the adjustment screw while making necessary adjustments, it can lead to inaccurate readings or insufficient engagement of the thermostat's mechanism. This lack of proper contact can result in the thermostat being unable to regulate temperature correctly, leading to operational issues such as overheating or underperformance.

While other factors like incorrect power supply, using an incompatible thermostat model, and regular wear and tear can contribute to thermostat failure over time, they are not as directly related to the immediate functionality and adjustment process of BJ thermostats. In contrast, the failure to properly engage the adjustment screw represents a critical user interface issue that can compromise the thermostat’s performance and longevity if not addressed during installation or routine adjustments.