How to Replace a Pressure Switch for a Shallow Well Water Pump

A pressure switch keeps the water pressure steady at the faucet.

A home that has a private water system uses a pump and pressure switch to deliver the water to the faucets. The pressure switch's job is to tell the pump when to turn on and off. It does this by monitoring the pressure in the plumbing and sending the power to the pump when the pressure drops below a set point. Since pressure switches are mechanical devices, they periodically need changing.

Things You'll Need

• Non-contact voltage detector
• Wrench
• Screwdriver
• Pencil
• Painter's tape
• Flashlight
• Emery cloth
• Plumber's tape

Instructions

1. Turn off the power to the water pump at the home's electrical distribution panel. Double-check that the power is off by touching a non-contact voltage detector to the wire's insulation.

2. Shut off a water valve that is upstream of the pressure switch. Open several faucets in the house to remove the water pressure from the system.

3. Loosen the bolt that holds the cover on the pressure switch, and remove the cover.

4. Mark each wire connected to the pressure switch for its terminal by writing the information on painter's tape and sticking it to the wires.

5. Loosen the electrical terminals and pull out the wires. Loosen the wire compression mechanism and pull the wires out of the side of the pressure switch.

6. Turn the whole pressure switch counterclockwise to loosen it from the pipe. Shine a flashlight down the plumbing pipe to check for any blockages. Remove any blockages before installing the new unit.

7. Clean the pipe threads with an emery cloth, and wrap new plumber's tape clockwise around the pipe's threads several times.

8. Screw the new pressure switch onto the pipe until it is very tight. Insert the wires through the side access holes and tighten the compression mechanism to hold them in place.

9. Push the wires into the terminals using the markings on the tape as a guide. Tighten the terminals.

10. Turn the pressure switch's small bolt to adjust the cut-out pressure. Turning it clockwise raises the pressure; counterclockwise lowers the pressure.

11. Turn the pressure switch's large bolt to adjust the cut-in pressure. Turning it clockwise raises the pressure; counterclockwise lowers the pressure.

12. Install the cover on the pressure switch and turn the power back on. Check for leaks at the connection to the water pipe.

Tips & Warnings

• The correct settings for the cut-in and cut-out pressures are located in the pump owner's manual.

References

• InspectAPedia: How to Find, Diagnose, Adjust or Repair the Water Pump Pressure Control Switch
• Schneider Electric: Pumptrol Pressure Switch; 2010