Schneider Electric Intermittent Power or Firmware Instability

Thermostat randomly reboots or restarts several times a day.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Loose 24 VAC connections, Marginal transformer capacity, Internal power regulator fault, Firmware bug causing watchdog resets

Safety: Turn off power before tightening any wiring.

Steps:

Inspect and tighten the R and C terminal screws on the thermostat backplate and at the HVAC control board.
Check that the 24 VAC transformer is adequately sized for all connected loads (thermostats, zone valves, relays); upgrade transformer if overloaded.
Update thermostat firmware to the latest version via app or gateway.
If reboots continue despite solid wiring and updated firmware, the internal power supply or processor may be failing; replace the thermostat.

Medium 3/5

Thermostat Power Supply / Main PCB

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