You can tell when a check valve is going bad on a submersible pump because it will cause your pump system to lose water pressure. The check valve prevents water from flowing back through the pump and into the well when the pump turns off. As the pressure in the water pipes drop, the pump will continuously run to restore the water pressure in the system. You need to replace the check valve to prevent the pump from burning out by running too much. Here is how a regular homeowner can replace the check valve on a submersible pump.
Turn Electric Off
You have to shut the pump down before you pull it from the well. Turn off the electricity to the pump before starting the repair job.
Remove Pump Assembly
The check valve for a submersible pump is located right above the pump at the bottom of the well. You have to pull the pump assembly out of the well in order to replace the valve. Open the cap covering the well. You will need a piece of ¾" or 1" galvanized pipe with a threaded end that can be screwed into a fitting at the top of the assembly to pull everything out of the well. The fitting on the assembly is about 4 feet below the opening of the well. Screw the pipe into the fitting and pull the pump assembly out of the well. The pump assembly includes the pump, the rubber hose attached to the pump, and the electrical wires used to operate the pump.
Remove Check Valve
The check valve is located directly on top of the pump between the rubber hose and the pump. The rubber hose is connected to an adapter that is screwed into the check valve with a hose clamp. Loosen the hose clamp and slide the rubber hose off of the adapter. If you're having trouble sliding the hose off, take a utility knife and cut the hose a little where it is attached to the adapter. This will release the pressure and you can pull the hose off of the adapter.
Take a couple of wrenches and place one on the nut on the check valve and the other on the nut at the top of the pump. Turn the check valve counter-clockwise to unscrew it from the pump. Hold onto the other wrench to keep the pump nut from turning while you are taking off the check valve.
Installing New Check Valve
The check valve will have an arrow on it to show you which way the water should flow through it from the pump to the house. Make sure the arrow is pointed away from the pump. Place plumber's tape on the threads of the check valve and screw the valve tightly into the nut on the top of the pump. Remove the adapter from the old valve and screw that into the new check valve. Make sure to put plumber's tape on the adapter's threads before screwing it into the check valve. Connect the rubber hose to the adapter with the hose clamp.
If you had to slice the rubber hose a little to get it off of the adapter, you need to remove the sliced part before you place the hose on the adapter. This will ensure you won't have any leaks where the rubber hose connects to the adapter that could cause you to lose water pressure later.
Put Assembly in Well
Slide the pump, rubber hose, and wires back down into the well. There will be an upside down U-shaped fitting on the rubber hose. This fitting slides over the top of a pipe sticking out into the well for an inch or so just below the frost line for your region. The fitting connects the rubber hose on the pump to the water line going to your house. Make sure the fitting is connected to the pipe.
Turn the pump back on and prime it by filling the water line up with water. Once the right amount of pressure has built up in the system, the pump will shut off. Don't run any water in the house for 15 to 20 minutes. If the pump doesn't turn on, you know the system is maintaining the pressure and the check valve problem is now fixed. For more help, contact a contractor, like Modern Pump & Equipment, for more help.