If you have a submersible pump for your well, it's supposed to go off as soon the water in your storage reaches a certain level. However, you can have a case where the pump keeps running unless the power supply is cut off, which shouldn't be the case. Running for too long elevates the risk of damage because of overheating and eventual wearing of the pump's bearings. If your submersible pump won't stop running, here are some of a few things you need to check and do to get it back in order:
An Open Water Outlet
If one or several outlets are open, releasing water from your storage tank, then your pump won't stop running. This is because of a continuous inflow and outflow of water from the pump to the open storage. Check your house to see if there are any fixtures and faucets releasing water as soon as the pump lets it out. Inspect outdoor watering systems and garden hoses for leaks, including any boilers. If any, turn the pump off and shut the water supply valves before calling in a professional to check and repair the leaking fixtures accordingly.
The Pump's Control Switch
A submersible pump's control switch is used for the automation of the pump. It is connected to the pipework supplying water to different points in your home such that it can detect the pressure level of the water and get the pump running when necessary. For most submersible pumps, the control switch operates a heavy-duty wall-mounted pump relay that in turn switches the pump on. A common mistake you (or someone else operating the pump) might make is to set a higher pressure than what the pump can achieve. This means that it will keep running to meet the pressure set on the control switch. Therefore, check the control switch to make sure that pressure has been set to the correct level as instructed in the manufacturer's manual.
The Water Level in the Well
A dry pump may keep in running when the suction it generates has no load (water) to up to the water supply system. If you notice the pump running yet there is no water being supplied to the storage tank or other outlets, then it is highly likely that the water level in your borehole has gone down. A pump running dry is at high risk of being damaged. Therefore, you should turn off the pump to allow the water in the well some time to gather.
If none of these things are able to stop your pump from running, contact a company that offers pump repair services.