Photo of a well pump pressure switchHow to Replace a Water Pump Pressure Control Switch
10 easy steps to replace a water pump control switch

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Water pump switch replacement:

This article describes how to replace a water pressure control switch which is not working properly or perhaps is not working at all. We describe and illustrate how to find the pump switch, then we detail how to identify, remove, and replace the water pump pressure control switch for both above-ground pump and submersible well pump systems.

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Water Pump Presssure Control Switch Replacement Procedure

Photograph of a water pump pressure control switch with the cover onIn the sketch at page top the water pump pressure control switch is item #4 - we show this switch in more details in photographs provided below.

[Click to enlarge any image]

How to Remove and Replace a Water Pump Pressure Control Switch

This article explains the detailed steps to follow in removing and replacing a water pump pressure control switch. If you want to take apart, inspect, and try cleaning up an old pump control, use the directions here to remove or reinstall it, use the information
at PUMP PRESSURE CONTROL REPAIR to inspect and clean the control.

Here are a few tips that will make removing and replacing the water pump control switch easier, and which will reduce the water spillage (or spray) into the room during this operation.

Really? Yeah. if you're like me you are replacing the entire pressure control switch assembly and its mounting tubing or the tubing that conducts water pressure to the pressure-sensing diaphragm on the switch base. However if you're like a few of our more adventurous readers and you want to replace just burned pressure switch contacts or a diaphragm with a hole in it, see this separate article:

  1. Turn off electrical power to the water pump. If you simply unscrew the pump control without first turning off the pump and taking pressure off of the water tank and pump, you will have a fountain of water squirting all over the place.

    If you make this mistake and if you can't easily simply screw the old parts right back in to stop the leak, (you'll only do it once) don't panic - it's just water. Just turn off the pump and open a nearby valve to take water pressure off of the system.

    If the pressure control switch is mounted high, say on top of a well pump which is itself on top of a water tank, all you need to do is take pressure off the water tank – don’t need to drain it fully.

Pressurtrol pump pressure control switch points in used but good condition (C) Daniel Friedman

  1. Disconnect electrical wiring from the water pump control

    Find the water pump pressure control switch
    : first of course we need to find the pressure control switch. The pump switch will be usually be located on the pump itself (above ground water pumps) or on a tee at the water pressure tank outlet. If your pressure tank and pump controls are not inside the building they may be located in a basement crawl area or outside in a well pit. (WELL PITS). On a building water pump-operated water supply system there is virtually always a pressure control switch somewhere; on some irrigation systems or other special designs the pump may operate only with an "off-on" switch and there may be no pressure tank and pressure control switch.

    Take a photo of your wiring connections before you touch anything, then you might as well as label the wires and perhaps make a little sketch showing which wires connected to which of the two or four terminals on the switch.

    Watch out: you can be killed by electrocution. Be sure that electrical power has been turned off, confirm that power is off using a neon tester or VOM. If you are not skilled and trained in this work, hire an electrician or plumber to do these tasks.

    Mark the electrical wires and their proper connection points on the water pressure control switch. If you're proceeding on your own, mark and label each wire and each terminal that it was connected to so that you can replace the wiring correctly later.

Photo of a water pressure gauge showing pressure below pump cut-in

  1. Remove water pressure from the water tank (see that gauge in my photo: if there's water pressure on your system you'll have it squirting all over the place if you don't remove pressure before opening any plumbing fittings: remove water pressure from the water tank and pump by opening a nearby faucet or tub, or by connecting a garden hose to the water tank drain and running the hose outside. You might not need to drain all of the water out of the water tank:

    • Water tank full drain down method #1:

      If the pump pressure control switch is mounted at the bottom of the water tank
      – you can
      drain the water tank completely, but watch out for losing pump prime on some older types of pumps
      – take some water into reserve containers in case re priming of an old jet pump is needed at the end of this repair.

      This will not be a concern the well pump is a submersible one down in the well since such pumps are self-priming.

    • Water tank partial drain down method #2:

       you can take the water pressure off of the water tank, down to say 5 or 10 psi, and speed up the repair process by following these steps:

      • Enlist the aid of an accomplice whose role we'll explain in a minute

      • Have all water pump control repair parts you might need close at hand and prepared for use
        • a new little riser pipe
        • a pipe plug of the same thread and diameter as the pump control mounting pipe you’re removing
        • Pipe dope or teflon tape
        • All new parts you intend to replace

Photo of the bottom of a pump control switch
  1. Unscrew the old parts 

      • Block leaking water with a finger or a pipe plug.

        As you remove them and water begins to flow out of the opening where the control was mounted, the accomplice simply puts his/her finger over the hole and keeps it there while you do your control checkout or prepare the replacement to screw in – it’s easy to hold back 5 psi with a finger over a small hole.

        If you don’t have an assistant, remove the old parts, and through the flowing water out of the threaded opening, screw in the pipe plug you bought for that purpose (cheap assistant) to close the leak, then go on to investigate the control or prepare and re-install the new one.

  2. Replace the pump pressure control parts with the new ones or the repaired ones you've got at hand.

    we like to prepare the new replacement parts with pipe dope or teflon tape before taking apart the old ones - that makes it quicker and neater in reassembling the pump pressure control switch with minimum water spillage.

Photo of the interior of a water pressure control switch showing the electrical contacts.

  1. Reconnect the electrical wiring to the water pump control just as the previous control was wired.

    For a 120V circuit, there will be four electrical wires, two line-in wires (hot and neutral wires) from the power source are connected to two screws which may be indicated as "Line" by markings on the switch, and two line-out wires (hot and neutral wires) bringing power out of the control and on to the water pump.

    Watch out: also, as the manufacturer (Schneider Electric for Square D Pumptrol wiring connections),

    Electrical equipment should be serviced only by qualified electrical maintenance personnel. No responsibility is assumed by Square D
    [ nor by ] for any consequences arising out of the use of this material. - Pumptrol Pressure Switch Installation & Wiring Instructions (2010), retrieved 1 April 2015, Schneider Electric USA 8001 Knightdale Blvd. Knightdale, NC 27545 1-888-SquareD (1-888-778-2733)

    Below is a simple wiring diagram example using a Square D Pumptrol installation schematic and a photo of a typical pump wiring hook-up.

    Watch out: If your pump pressure control switch is controlling a higher capacity submersible well pump, the electrical wires leaving the control may feed a separate heavy duty pump relay switch rather than going directly to the water pump. Well pump relay control panels are discussed separately

Square D Pumptrol wiring diagram - / or Pressurtrol pump pressure control switch points in used but good condition (C) Daniel Friedman

  1. Turn off any faucets you opened earlier to remove pressure from the water system.

  2. Turn the water pump electrical power back on

Photo of a water pressure gauge

  1. Watch the water tank pressure gauge, and when you have about 20 psi in the system (our gauge reading shown here is a bit too high) turn the water pump power back off and check the system for leaks.

    Wipe dry any wet parts, especially around the bottom of the pump control and where the pump control mounting pipe or fitting mounts into the water pump or water tank fitting.

    Inspect your plumbing connections closely for water seeping out - if you have leaks go back to step 1 or 2 and re-make your connections with better preparation of the threads with pipe dope or teflon tape.

    If you need to adjust the operating pressure range of the pressure switch see "How to Adjust Water Pump Pressure" given just below.

  2. When you confirm that there are no water leaks, turn your pump power back on and the system should operate normally.

    IF the well pump is still not turning on and off properly you probably have another or a different problem. See the other water pressure and water pump control diagnostic articles listed at the left of these pages.

A Guide to Building Water Pressure by Adjusting or Repairing the Water Pump Pressure Control Switch

Reader Question: how do I replace the well pump pressure control switch shown in this photo?

Pump pressure control switch mounting details (C)

Regarding your text stating that

"Other pressure control switches may be bolted right to the pump motor and may use a flexible plastic or copper tube to transmit water pressure to the switch....."If this pipe (usually ¼” or 1/8” IPT diameter) is clogged...."

There is no such tubing [visible] on my system (see the photo at left), yet switches I looked at, at mention "1/4 in. pressure connection".

Am I going to run into a problem if I don't have this tubing? Can I still use such a switch? Here is a picture of back of the pressure control switch.

Reply: You'll be fine with a new pressure control switch, a close nipple (iron pipe thread) of brass or galvanized steel, and some teflon pipe tape or pipe sealant.

It looks like your switch a 1/4" rather than 1/8" diameter iron pipe though I'm not quite sure from just the photo. Larger diameter gauge and pressure switch mounting pipe means less likely for the pipe itself to clog with sediment, rust, debris. But the principle is the same.

Brass close nipple

The reason you don't see a "tube' or mounting pipe is that your pressure switch connecting base (red arrow in photo above) is screwed directly into that galvanized iron tee (green arrow), almost certainly using a "close nipple". See our brass close-nipple photo at left and see the white marking line in photo above showing where that part is hidden.

A close nipple is nothing more than a very short section of threaded pipe. (photo at left). For comparison, here is a photo of a standard pipe nipple, also made of brass in this case. You can see another close nipple in your photo above - between the galvanized pipe tee and the metal to plastic bushing that adapts the whole setup to fit into that white plastic fitting (between the green and yellow arrows in our annotated photo).

When you unscrew the pressure control switch from the pipe tee shown in your photo, the close nipple will either come out with and remain attached to the switch bottom or it will remain screwed into the tee. If the close nipple remains screwed into the tee and does not move at all, you may be able to screw the new switch right onto it.

Watch out. If the close pipe nipple moves in the tee but you try just leaving it in place you may have a leak when you repressurize the system.

To change out the pressure switch shown in the photo above, you'd turn off power, remove wiring from the switch, drain pressure off of the water pressure tank to reduce the spillage when you remove the switch, then carefully unscrew the switch (attach a wrench to the fitting on the bottom of the switch) from the pipe. I'd probably use a small pipe wrench or Vise-Grip™ tool to remove the old close nipple from whichever side of the fittings it remained, and I'd install a new one to be sure my installation didn't leak.

Your plumbing supplier can supply you with both a threaded pipe nipple of the proper diameter and a new pressure switch (whose bottom typically includes a mounting fitting sporting a female NPT threaded fitting intended to screw onto a pipe, tube, or close nipple). (Some pressure switches might be supplied with a male threaded bottom fitting instead of female - check the parts before you leave the supplier so you have what you need to make the new connection.)

Watch out: because your whole setup of switch and gauge are mounted in a larger diameter PVC plastic pipe fitting (yellow arrow in photo above), if the switch is hard to unscrew you risk breaking that plastic part - which would mean more work to repair the system. Avoid this problem by using two wrenches, one holding the metal pipe tee into which the switch base is screwed, and the other turning the switch base against the tee. That will avoid stressing and breaking the plastic.

Use a bit of teflon tape or pipe dope when mounting the new switch but don't blob pipe dope or tape into the switch bottom where it might block the sensing switch diaphragm orifice.

Is a Pressure Control Switch Required in Water Pump Installations?

Reader Question: the switch that turns my pump on and off broke off: can I just wire the pump directly?

Hi I have a sta rite well pump that I had to pull up to replace the foot valve in but after replacing it and putting the pump back in my switch that turns it on and off broke and the pump wouldn't turn on. So my father in law has the same pump but doesn't have a switch it's just wired in with the 4 screw diagram in this tutorial so my question is how would I wire this so it will come on and just just by pass the switch and let the breaker control on\off? Thanx for any help - R.V. 10/17/2013

Reply: Yes. Where to find Pentair's Sta-Rite well pump installation guides & wiring instructions:

I'll be glad to help,R.V., but to do so I need to know which pump you have installed (there are several Sta Rite models); we'll review the manufacturer's installation and wiring instructions. Since I'm not sure what's going on at your pump or what you meant by "this tutorial", and not knowing just what broke, I describe two possible cases:

  1. If you are talking about the pump power on-off switch, it should be trivial to wire the pump through an external 120V (or if needed 240V) wall mounted electrical switch. In fact there should already be such a switch installed at or near the pump;
  2. If you are talking about having broken off a pressure control switch, you need to buy and install a new one.

Watch out: in general we would not want to wire up a well water pump to simply be "always on" nor would we wire a home water pump to run without a pressure control switch for several reasons:

  1. It's dangerous - risking an electrical overheat, melted wires, short circuit, fire or shock.
  2. It's dangerous - risking bursting a water pressure tank if excessive pressures are created in the system, particularly if the pump is a powerful model or a typical submersible unit;
  3. We risk a burst pipe, leaks, building damage
  4. We risk damaging the pump
  5. We are probably violating the manufacturer's instructions and thus the pump warranty too.

Certainly a review of typical installation instructions for a Sta-Rite deep-well jet pump makes amply clear that the company expects the pump to be powered and controlled through a pressure control switch.

In an emergency I would not hesitate to wire a pump to be turned on and off manually provided that a competent person were standing by the power switch to turn the pump on and off as needed; I would never leave such an emergency hookup in the "ON" Position for the reasons cited above.

Send me some sharp photos of the pump, its identifying labels, and also photos from a distance so I can see how the pump is hooked up and wired presently. When I have seen which pump you have, we can figure this out together.

If you want to contact the company directly, Sta Rite well pumps are provided by Pentair under the brand Sta-Rite - their website is at and their page on water pumps and systems is at


Continue reading at WATER PUMP PRESSURE CONTROL ADJUSTMENT or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see WATER PUMP PRESSURE CONTROL REPAIR to diagnose pressure switch problems or to replace the pressure switch contact relay parts or diaphragm.

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WATER PUMP PRESSURE CONTROL REPLACE at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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