A leaking water heater from the top can indicate an issue with the temperature and pressure relief (T&P) valve. The T&P valve is a safety device that releases excess pressure from the water heater tank to prevent explosions. If the valve is faulty or the pressure in the tank is too high, it can lead to a leak at the top of the water heater. Other potential causes include a cracked or damaged water heater tank, loose connections, or a malfunctioning heating element. Identifying the exact cause is essential to resolve the leak and ensure the safe and efficient operation of the water heater.