Drazice water heater display shows AL1 or a general alarm icon; unit may continue to operate with reduced function.

Safety: Always disconnect power before touching internal wiring.

Steps:

• Note any accompanying codes or icons that may indicate which sensor or function is affected.
• Power-cycle the heater and observe if AL1 returns.
• Inspect accessible sensor wiring (NTC sensors on tank, inlet, outlet) for loose connections and secure them.
• If AL1 appears sporadically but the heater operates normally, monitor performance. If it becomes frequent or is accompanied by heating issues, have a technician test all sensors and the control board.