How to Test a Water Well Pressure Switch
The water well pressure switch is responsible for controlling the well pumps operation. Generally, the switch is connected to the pressure tank on the water system. Here a small 1/4-inch in diameter pipe nipple creates the plumbing connection, plumbed separately into the water system is a pressure gauge.
What You'll Need:
- Voltmeter
- Take off the cover that is on the pressure switch. You can use the voltmeter to check the voltage level that is coming into the switch as well as the power going to the well pump. Put the voltmeter in the "volts" position then place the red lead into the connector marked "volts". Put the black lead into the connector identified as "com" or common, depending on your specific model.
- Locate the power feed wires. You should see two sets of contacts on the pressure switch that are both electrically tied to the screws below them. There will be an inside set as well as an outside set. The set of wires are terminated to one each set of screws all on the pressure switch. One pair of the wires is for the power feed, while the other pair goes to the pump motor.
- Touch the red lead that is located on the meter to one of the screws that are connected to the power feed wires. Next, touch the black lead coming from the meter onto the other wire of the matching pair. Look at the meter, it should read 220VAC. Last, take off the meter leads.
- Open any faucet in order to drain water from the system. At the point the pressure switch contacts should be touching and the pump should be running as well. Now touch the meter's leads to the opposite set of contacts at the location where the wires are running out to the water pump. Look at the meter, it should read 220 VAC again. If the meter does not read the same voltage as the power feed, there could be a problem with the switch.