Safety: Turn off power at the breaker before removing the thermostat from the wall.

Steps to troubleshoot E16 (display fault):

1. Check viewing angle and brightness: Some models allow brightness adjustment. Use the app or buttons (if visible) to increase brightness and see if the display becomes readable.
2. Power cycle: Turn the breaker OFF for 1 minute, then ON. Observe whether the display briefly lights during boot.
3. Inspect for physical damage: Look for cracks in the display or signs of impact. If the glass is broken, the display assembly must be replaced.
4. Reseat display connector (advanced): With power OFF and thermostat opened (if serviceable), gently reseat the ribbon cable between the display and main board.
5. Replace thermostat: If E16 persists and the display remains unreadable, replace the thermostat. The display and driver are not typically field-repairable.

Note: You may still be able to control the thermostat via the Stelpro app even if the local display is faulty.

Thermostat shows E16 and the backlight or display does not turn on properly

Possible Causes