How to Adjust a Well Pump's Pressure Switch
If you get your water from a well, chances are you're using some type of well pump to extract the water from down below. No matter what brand your pump, Square D manufactures the vast majority of the pressure switches. From time to time, those switches will need adjusting, and you can do it all yourself. Does this Spark an idea?
Things You'll Need
- Phillips screwdriver
- Slotted screwdriver
- 3/8 inch nut driver or socket wrench
Instructions
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1
Locate the pressure switch on your well pump. It is typically located toward the rear of your well pump, closest to the storage tank. During operation, it is crucial to monitor the pressure switch to see where and when it shuts itself off and turns itself back on.
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2
Determine whether you need to adjust the cut-in pressure (which starts the pump), the cut-out pressure (which stops the pump) or both. You will be able to tell after finishing Step 1, as this will clue you in to your pump's current cycle (either short or long).
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3
Figure out what pressure your air bladder requires (if applicable) based on the manufacturer's recommendations. Schneider Electric, makers of the Square D pressure switch, recommend setting the air pressure in the bladder to 2 psi below the new desired cut-in pressure when instructions are not available.
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4
Set the new air pressure by first turning off the power supply. Drain the water from the pressure tank and then take a pressure reading of the tank using a pressure gauge. To reach the proper pressure, add or remove air using the air valve.
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5
Remove the cover of your pressure switch with the power still off. Inspect the switch for leakage, as no fluid should be leaking from the diaphragm/flange area. The flange should be corrosion-free and the area should be virtually spotless, with no wet spots or standing water.
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6
Check the plumbing connections for flange corrosion and make sure that the fittings are secure, with no white (lime) deposits. Check the electrical connections next, looking for pinched or frayed wires and/or cracked insulation. There might also be insects, insect nests, or insect contamination, which will need to be cleaned up if present.
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7
Check the system pressure using a pressure gauge once Steps 5 and 6 are done and all problems/issues are remedied (i.e. cracked wires are fixed or corrosion is eliminated).
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8
Turn the range nut R with your 3/8 inch wrench to adjust the pressure. Clockwise turns will increase cut-in pressure, while counter-clockwise turns will decrease cut-in pressure. If the original setting was 20 to 40 psi and you want it to be 30 to 50, it will require 3 1/2 clockwise turns. If the setting was 20 to 40 and you want 40 to 60, turn the range nut 8 to 8 1/2 turns clockwise. Finally, if the setting was 30 to 50 and you want it at 40 to 60, turn the range nut 3 1/2 times clockwise. Replace the cover and restore the power to confirm pump system operation.
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9
Adjust the pressure switch to increase or decrease the cut-out pressure, while still maintaining the cut-in pressure (if necessary), using your 3/8 inch socket or nut wrench. Repeat Steps 5 to 7, then turn differential nut D clockwise for higher cut-out pressure, or counter-clockwise for lower cut-out pressure.
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10
Replace the cover and restore the power to confirm pump system operation. Open a tap or spigot to confirm water flow.
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11
Monitor the system to ensure the settings are as desired. You can open a faucet and drain water until the pump turns on, and then turn off the faucet. When the faucet is off, monitor the system pressure to see where the pump turns itself off. Repeat Steps 8 and 9 as necessary.
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Tips & Warnings
If you're lowering the pressure setting, remember that most bladder tank water systems are designed for the bladder pressure to be 2 psi below the cut-in point when there is no water in the tank.
References
- Photo Credit Water well, Romania image by Oren Sarid from Fotolia.com
