It depends on a variety of factors, including the make and model of the pump, how often it's used, the water pressure and flow rate, and the quality of the water. In general, you can expect a submersible well pump to last for around 7-10 years. If your pump is older than that and needs to be replaced, it's a good idea to have it inspected by a professional to ensure that there are no underlying issues that could cause problems down the road.