Thermostat backlight or display flickers or dims randomly while powered.

Safety first: Isolate power before removing the thermostat from its backplate or opening the housing.

Steps to diagnose and fix:

• 1. Check supply stability: Verify that the mains or 24V supply is stable and within specification. Correct any wiring issues causing voltage drops.
• 2. Reseat connectors: If accessible, gently reseat any ribbon cables or connectors between the display module and main PCB.
• 3. Adjust brightness: Lower the backlight brightness in settings to reduce load on the backlight driver.
• 4. Replace thermostat front module: If flicker persists and is localized to the display, replace the front panel or entire thermostat, depending on model design.

When to call a professional: For in-warranty units or if supply issues are suspected, consult an electrician or Danfoss service.