The answer to 'sump pump not working' is that there are several common causes, including a faulty pump, clogged intake, tripped circuit breaker, or issues with the float switch. Symptoms may include the pump not turning on, running continuously, or not pumping out water effectively.
To troubleshoot, first check the power supply and circuit breaker. If the pump has power, inspect the float switch to ensure it's moving freely and triggering the pump. You may need to clean out any debris or obstructions around the intake. If the pump itself is faulty, it will likely need to be replaced by a professional plumber.