Safety first: Disconnect power before removing the front panel.

Dry the keypad: If condensation is visible, gently dry the surface and allow time for internal moisture to evaporate.
Check cable connection: Ensure the keypad ribbon cable is fully inserted into the connector on the display or main PCB.
Test operation: Restore power and test each button. If some keys still fail, the keypad assembly likely needs replacement.
Replace UI module: Install a new Hewalex user interface module following manufacturer instructions.

Display is on but buttons do not respond or respond intermittently.

Possible Causes