Water pump switch installation or replacement:

How to Replace a Water Pressure Control Switch that Sticks "ON" or "OFF" or is irregular.

Well pump & water tank pressure control switch repair or replacement procedures & wiring.

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.

Water Pump Pressure Control Switch Location

Where on the plumbing system should the pressure control switch be located & mounted?

Locate & mount the water pump pressure control switch close to or on the water pressure tank

Except for special installations such as constant pressure water pump systems in-well systems that do not use a conventional water pressure tank or water storage tank, the pressure control switch should be located as close to the pressure tank as possible.

Failure to do so can result in a pressure control that does not function properly in response to water use, possibly causing surging or switch damage.

Typical pressure control switch locations include the following placements on the water supply system.

There are several considerations when deciding where and how to mount a water/well pump pressure switch:

Photo above: the gray pressure control switch is mounted on a galvanized pipe nipple and street-ell that is in turn screwed into the water pump body at a tapping provided by the manufacturer.

1. The switch should be close to the water pressure tank
   
   Otherwise the pump may not respond properly to changes in water pressure and you may have short cycle or other pump issues.
2. The switch pressure sensing port needs to connect to a small pipe or tube
   
   that at its other end connects to a water pressure source on the pump body, on the pressure tank, or on water piping close to the pressure tank
3. The switch needs to be readily accessible
   
   for wiring and for adjustment.

Photo below: the pressure control switch is supported on a bracket and a plastic tube connects the pressure switch sensing port to the pump body at a tapping provided by the pump manufacturer.

1. On the jet pump itself or at the pump, supported by a separate bracket (photo above)
   
   or supported by a short pipe nipple screwed into the pump's body where the nipple can sense the pump's outlet water pressure - suitable for 1-line and 2-line jet pumps located themselves at or close to the water pressure tank.
   

2. On a water tank tee
   
   at the bottom of the water pressure/storage tank outlet. Photo above: the pressure switch is mounted on a pipe nipple at the tank tee that is in turn installed at the water pressure tank.
   
   The tank tee may provide connections for the pressure control switch , for a water pressure gauge, for a pressure relief valve, and for connections to incoming water from the pump, water inlet to the water pressure tank, and water outlet to the building.
3. On the water tank itself,
   
   at a tapping provided for that purpose by the manufacturer.

4. On water piping close to the water pressure tank:
   
   as illustrated in our photo above, this is a common location for pressure control switches serving a submersible well pump system.

 

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

What's the allowable distance between water pressure tank and the pressure switch?

Is there an actual limitation for the distance between a pressure tank and the pressure switch?

I have an artesian well located in a pit about 90 feet from where the water supply enters my house.

Currently the pressure tank and pressure switch are located in the pit right beside the well cap. I need to replace the tank and would prefer to leave the pressure switch in the well pit while putting the new tank in the basement of the house where the water supply enters. (Aug 14, 2014) sfurbish55

Reply: 12-18" optimum vs problem (too great) distances between the water pressure switch and pressure tank

SF

Probably there is a practical distance limit but in reading various installation instructions I have not found a single quantitative specification or standards. Instructions generally say locate the pressure control switch close to the pressure tank.

Mounting the pressure switch on the tank tee at the bottom of the water pressure tank is quite common and respects the most-common pressure switch installation instruction we've found that pretty much all say:

Install the pressure control switch at a suitable pipe tee or tapping that is located as close to the water pressure tank as possible.

You can see in my photo above that the pressure switch as mounted on this tank tee will be just inches from the water pipe's entry to the water pressure tank.

Mounting the pressure control switch on nearby water piping, within 12 to 18 inches is ideal provided that there is no shutoff valve on the piping between the pressure control switch and the water pressure tank.

At some installations the pressure control switch is physically mounted on a bracket on the water pump itself.

In those cases there will be a short small diameter tube that connects the sensor port on the bottom of the pressure control switch to the water pump itself at the injector chamber where it can sense water pressure (photo below), or it may connect the water piping at or very close to the water pressure tank.

In my experience that means that the pressure control switch is no more than a few feet away from the water pressure tank.

Watch out: I would not mount the well pump pressure control switch remote from the tank. Doing so will give not only great difficulty in turning the pump on and off properly when water is being used, it also risks damaging the pump or water tank and in extreme cases might cause an over-pressure in the system that would be unsafe or cause leaks.

Research on Pressure Switch Mounting Location

• AWH, DIAPHRAGM WELL TANK INSTALLATION MANUAL [PDF] American Water Heater, N Perma Tank Retrieved 2018/06/22, original source: http://www.americanwaterheater.com/media/68148/205621-000.pdf
  
  Excerpt: Install tank as close as possible to the pump pressure switch to reduce friction loss and elevation difference between the tank, water supply main, and switch.
• Cycle Stop, Correct Pressure Switch Placement Stops "Bouncing or Telegraphing (Web article) Cycle Stop Valves Co., 10221 CR 6900, Lubbock, Texas 79407 USA info@cyclestopvalves.com Tel: 806-885-4445 - local backup copy saved as Pressure-Switch-Placement-CycleStop.pdf

 

Can the pump control switch be mounted horizontally instead of vertically?

Is it OK to install the pump pressure switch in a horizontal orientation vs the normal vertical orientation? In other words, instead of mounting it straight above the tank tee, use an elbow and additional nipple is the connecting nipple is horizontal instead of vertical. On 2020-06-05 by Doug

by (mod) - yes

Doug

Pressure control switches like the Square D unit shown on this page can be mounted horizontally or vertically.

See WATER PUMP PRESSURE SWITCH MANUALS

to find the installation instructions for your specific switch and you can confirm the permitted mounting positions.

 

Is it OK to put the pump pressure control switch at the top of the water pressure tank?

Our reader asked: My plumber installed a new bladderless tank for our well pump 2 mo’s ago. He put the pressure switch directly on the tank near the top, not on the water line feeding the tank. Is this okay? - On 2018-06-21 by Russ

Answer by (mod) - Yes

Yes, that's fine, Russ since both the air and water in the tank will always be at the same pressure. Key is that the pressure switch is mounted close to the pressure tank itself - as it is indeed in the photo we include here as an example of a pump pressure control mounted close to the very top of the water pressure tank.

If you can tell me the model number of your Pentair tank we (or you) can check the water pressure tank's installation manual to see what the manufacturer recommends.

followup by Russ

Thanks Dan, that’s what he told me but everyone else I talked to said it wasn’t right. This is not a tank with a bladder so I think that is what is confusing.

In the manual it suggests the switch be installed on the inlet line to the tank. This all started because we noticed the pump would run continuously when taking a shower.

He noticed the switch was set to high (65).

He did the draw down test & all our pump will produce is 4 gpm.

Says our pump is getting weak. He installed it 8 years ago & claims that is about average.

8 to 10 years?? So that’s why I was wondering if something else caused the pump to wear out.

by (mod) - pump getting "weak" ?

Right,

But it makes no difference to the pressure control switch whether it's on a tank using an internal bladder or not. The switch simply responds to pressure sensed at its sensor port.

At WATER PUMP PRESSURE CONTROL REPLACE we include instructions on switch replacement

And at WATER PUMP PRESSURE SWITCH REPAIRS

you'll find links to PDF files giving pressure control switch installation instructions from the switch manufacturers.

I'm going to review the manufacturer's instructions to see if they raise any question about pump switch mounting location. To date the main constraint I've found is that the switch needs to be mounted as close to the pressure tank as possible rather than remote from it.

The pressure control switch can last 30 years or longer, or fail in a few months. Early "failures" are usually due to

1. debris clogging the pressure switch sensor port opening - the switch fails to respond to changes in pressure

2. arc burning - due to excessive short cycling due usually to a waterlogged pressure tank

by Russ

Pentair AW42T bladderless tank. we have a 3/4 hp Sta- rite pump. Should we go with a1 hp.

He suggested not because it could change levels in the well over time. Does that sound possible?

by (mod) - manual for Pentair AW42T bladderless tank.

The Pentair manual for this tank series shows several installations including one in which the switch is attached to a bracket on the pump and monitors tank pressure by a tube connected to the pressure tank. The manufacturer didn't anticipate a direct on-tank mount nor do they prohibit it.

See your manual at one of these lists:

• WATER PUMP SWITCH INSTALLATION MANUALS
• WATER PUMP & TANK I&O & REPAIR MANUALS

Right, Pentair and other water pressure tank manufacturers (cited below) typically suggest a "standard" installation in which a tank tee or "tank cross" is connected to the bottom of the water pressure tank.

When that fitting is installed, because it provides a tapping for the pressure control switch, that's a correct and easy place to mount the control. I show an example in my photo below.

OPINION: But it makes no difference to the pressure control switch whether it's on a tank using an internal bladder or not. The switch simply responds to pressure sensed at its sensor port.

At WATER PUMP PRESSURE SWITCH INSTALL / REPLACE we include instructions on pressure control switch installation or replacement .

And at WATER PUMP PRESSURE SWITCH MANUALS you'll find links to PDF files giving pressure control switch installation instructions from the switch manufacturers.

A review the manufacturer's instructions to see if they raise any question about pump switch mounting location to date shows that the switch needs to be mounted as close to the pressure tank as possible rather than remote from it. But none of the instructions we found said a word about where on the pressure tank the switch should or should not be mounted.

A water pump pressure control switch can last 30 years or longer, or fail in a few months. Early "failures" are usually due to

1. debris clogging the pressure switch sensor port opening - the switch fails to respond to changes in pressure

2. arc burning - due to excessive short cycling due usually to a waterlogged pressure tank

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Continue reading at WATER PUMP PRESSURE SWITCH INSTALL / REPLACE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these WATER PUMP CONTROL SWITCH LOCATION FAQs - questions and answers about where to put a well or water pump pressure control switch and sensor.

Or see these

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