Photograph of a water pressure tank air valveWater Pump Controls & Switches FAQs
Q&A on Water Pump & Well Controls & Switches

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Well Pump & Water Pump Control & Switch Questions & Answers:

Q&A about how to identify, use, fix or replace the various controls & switches used on well pump & water pump systems & equipment.

This article series describes and identifies the switches, controls, and safety devices used on water tanks and water pumps such as the pump pressure control switch, pump motor relays, water tank relief valve, water tank pressure gauge, water tank air volume control, and water tank air valve.

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A Dictionary of Water Pump & Water Tank Controls, Switches, & Attachments

Water tank cross unit or tank tee (C) D FriedmanThese questions & answers about water pump controls were posted originally at WATER PUMP CONTROLS & SWITCHES

On 2017-09-14 by (mod) - How do I replace my water pump pressure control switch.?

Karen at


we give details about removing and replacing an pressure control switch. Please take a look, let me know if ANY questions remain and I'll be glad to answer further.

On 2017-07-30 by Karen

How do I replace my water pump pressure control switch.?

On 2017-05-11 by (mod) - manual lever oin side of pump switch used to turn the pump back on?

it's also possible that you're well I'm exhausted. Try getting the system off for a few hours or longer if if you. Then see if you can reset and turn the pump back on

On 2017-05-10 by Mark

We have a 50/70 cut off switch with a manual lever on the side to switch the water on when it shuts off which it has been doing now water won't come back up at all

I'm thinking the pump is dead any information would be greatly appreciated thank you

On 2017-05-03 by (mod) - One well, two homes, individual tanks, each their own power


Gee no, I'd like to see that myself - I think you're saying that a single pump can be switched on by a pressure drop at either of two homes that it serves from a single well. Right?

On 2017-05-03 by John

Double throw, pole contactor One well, two homes, individual tanks, each their own power (separate meters) Any photo's on this kind of hook up?

On 2017-04-16 by (mod) - Is water what the pressure switch sensing to cut off


System water pressure is conducted via a small diameter tube or pipe to the bottom of the pressure control switch. There the pressure operates a spring-pressed diaphragm that in turn opens (turns off) or closed (turns on) the switch in response to water pressure.

On 2017-04-16 by Manny

Is water what the pressure switch sensing to cut off

On 2017-02-17 by Yilliang Peng -

Yilliang Peng said:

Thank you so much for all the information regarding pump controls! My wife and I are trying to figure a lot of this out on our own and so thank you for the simple explanations of how to adjust the water pump pressure -- that was super useful!

Any information of a reliable site where I could get some materials? Thanks!

On 2017-01-15 by (mod) - pipes broke, now now water in the house


Did the pump run continuously while dry? That's enough to burn up the impeller or motor.

On 2017-01-15 by Marca g seal

had pipes break on well that goes to house had then repaired now we have no water into the house the well seen to not turn on? two repaired men in a bill of 2000 dollers still no water from well

On 2016-10-02 by Anonymous

How do I connect single phase water pump

On 2016-07-10 by (mod) - 300L auto volume CONTROL "AVC".


Yeah my spell checker would be better turned off.

The snifter valve system has two components (Search for SNIFTER VALVE to read details" - an air inlet inside the well in the well piping above the well water level, and an air release valve, usually at the air volume control (AVC) or at a schrader valve (looks like a tire valve) on the well piping near the tank.

If your snifter valve in the well fails you'll ultimately lose the air charge in the pressure tank - the tank will be waterlogged and the pump will short cycle.

If your air release valve stops working excess air in the system will ultimately discharge at the faucets.

From your description it sounds like a water-logged system - so yes I suspect a clogged snifter valve in the well.

On 2016-07-10 by Mike Riddle

Sorry, didn't edit. Spell checker kicked in. Should have read "300L auto volume CONTROL "AVC".

I have a 300l account with a snifter valve. Instead of air being released I am getting a stream on water from relief port until pressure falls to 30 psi. Could I have a bad snifter valve?

On 2016-01-30 by Sherri

Pentair controller, makeing ticky noise and no water beong pumped?

On 2015-11-14 by Anonymous

Randy search inspectapedia.Com for

No water pressure

To see a list of diagnostic suggestions

On 2015-11-13 by randy

i have a private well. what will cause me to loose all pressure, i turn the regulator and it will come back on

On 2015-09-14 by (mod) - if a 115v float switch is hooked only to one leg of power will that over time damage the pump motor?


On 2015-09-14 by joe

have a 1.5 hp groundfos deepwell pump 800ft that pumps in a holding tank

if a 115v float switch is hooked only to one leg of power will that over time damage my moter being theres still 115v

On 2015-07-07 by Kenny

I have a well pump pressure switch that has a larger gap 25-50 psi (it says its a 30-50 under the cover)

The gap nut (smaller nut) is loosened all the way and the spring is always loose, yet I can't seem to close the gap and make this switch run at 30-50.

I'm not sure where to go from here since the switch is very responsive (always cuts in at 25 and out at 50). What could be the problem.

I think that I should note this is a new system to me so I don't know if the switch ever worked or what adjustments have been made.

On 2015-06-24 by (mod) - water-on-demand system

Indeed, Anon, there are well pump systems that omit a pressure tank and include a small control device that turns the pump on and off in response to opening of a faucet.


120PSI is way too high for a common residential water piping system and risks leaks and water hammer damage.

On 2015-06-23 by Anonymous

I wish to setup a water-on-demand system in which whenever a faucet is opened the 65' deep well pump comes on and whenever it's closed the well pump shuts off.
Appreciate suggestions on equipment to acquire.

Forgot to mention that the well pump delivers 120psi of pressure.
Don't want to use a bladder type pressure tank, just a straight connection from the well output to the faucet.

On 2015-06-23 by Nick

I wish to setup a water-on-demand system in which whenever a faucet is opened the 65' deep well pump comes on and whenever it's closed the well pump shuts off.
Appreciate suggestions on equipment to acquire.

Forgot to mention that the well pump delivers 120psi of pressure.

I wish to setup a water-on-demand system in which whenever a faucet is opened the 65' deep well pump comes on and whenever it's closed the well pump shuts off.
Appreciate suggestions on equipment to acquire.

On 2015-06-06 by Cindy

What would cause a pump to not switch on sometimes? We have a well at the lake house. Can be there all weekend or several days and everything work just fine, or just as likely, at least once or twice during that time we lose all pressure, walk out to the well, see the pressure gauge WAY below the setting where it should kick on.

All it takes is a tap on the box on the side of the tank and it immediately kicks on, pressures up and there's no further problems, until the next time it happens, which could be 8 or 10 hours, the next day, or not until days later.

The inconsistency is frustrating, but at least all it takes is a tap to make it come back on.

On 2015-05-21 by Tom Henderson

can i wire 2 separate pressure switches and tanks to the same pump

can i wire 2 pressure switches and pumps to the same pump

Question: my well pump starts "skipping" (short cycling) at the cut-out pressure.

When my pump reaches the shut off point, it starts skipping......stuttering, then shuts off. I thought maybe the water filter was dirty so I changed it. The pump still stutters. I know ts cannot be good for the points. Any suggestions? Thank you for your time - S.D., Florida

Reply: things to check when the well pump chatters or skips at the top end of the pump pressure cycle

A competent onsite inspection by an expert usually finds additional clues that help accurately diagnose a problem with a well pump whereas by email our reply may be more of a "guess". That said, here are some things to consider:

Other possible problem sources that cause a pump to chatter or cycle at the end of the pumping cycle:

Let us know what you find - what we learn will help other readers diagnose and fix well and water pump problems.

Question: How to wire up my well pump switch to run when the rainbird water computer turns on

I have a rainbird water computer that I need to switch on a pump at the same time that it opens the electric water tap. Pump uses 220V so I need to get some relays. How do I wire these up? - Godfrey 11/7/11


Geez Godfrey,

I don't think I quite understand the question. Do you have the Rainbird water computer instruction and wiring guide? Or can you tell me the model number so we can look for those instructions as a starting point?

At least some of the Rain Bird timer systems - the ones we looked at, do not ask for a direct wired connection to a well pump. The timer is independent, and simply opens a valve that allows water to flow into an irrigation or other watering system. In general, if you have a water pump and pressure tank set up those components will automatically turn on the pump in response to a drop in system water pressure, without having to do extra control wiring at all.

If you don't have the instructions for your particular Rain-Bird equipment, contact Rain Bird Corporation at 6991 East Southpoint Rd., Tucson, AZ 85756, Tel: (520) 741-6100, or at 970 West Sierra Madre Ave. Azusa, CA 91702, Tel: (626) 812-3400 - the company's online provides links to manuals and documents for their equipment.

Question: What size of well pump pressure control switch should I use?

How does one know which pressure switch to use? a 20/40, 30/50, or a 40/60? I have a 30/50 and would like to use a 40/60. Would this damage my system or just give me better water pressure? - Steve B. 5/12/12


Steve. you'd select a water pressure switch among the three choices you list based on a balance between the desired pressure in the home (taller home, long piping runs benefit from higher pressure at the tank), and the capability of your water pump. Typically you can use any of the three without a problem, as long as you make sure that your pump is able to reach the cutoff pressure. If it cannot, but you're close, you can adjust the pressure control switch as needed. A safe bet is the 30/50 switch.

Question: water pump switch clicks and moves side to side

(Dec 28, 2012) karen junker said:

i have a question ;-) water pipes going to two tanks froze and broke, so i replaced everything exactly how it was and now,the pressure switch will cycle normal three or four times,

pressure is good water is good, everything is good for a couple of hours and then all of a sudden the switch next to the breaker box will just start clicking side to side like it is trying to throw the breaker.

it will keep doing this until i turn the breaker off. EVERYTHING is new, pump, breaker, tanks, pressure gauges pressure switch... i dont know what to do... no leaks nothing ?

please help


Watch out: Sounds a bit scary. Turn everything off immediately.

I'm concerned that everything is not exactly as before, something's not wired correctly. If an overcurrent is unable to trip a breaker your building could suffer a fire.

I'd ask a licensed electrician familiar with well pumps & controls to go over wiring, equipment mounting, and the operation of relays in the equipment.

Question: Davey Rainbird 110/240V 10A Water Tank Pump green light flashing

(Apr 22, 2014) Davey Rainbird 110/240V 10A Water Tank Pump said:

The green light is flashing on our Davey Rainbird water tank pump and we lost water pressure, can anyone shed some light on this fault & know the solution to fix please.

Reply: Davey Rainbird product & information sources:

Anon: we took a look at Davey Rainbird, an Australian / New Zealand company - with products and presumably support "all over the world" -

the company's website is - and I can see why you ask, it's not easy to find contact information nor an installation and service manual at the company's website. At least not easy for me.

Searching the company's site for Davey Rainbird returned ... you guessed it, zip. Nothing.

After pounding around in the Davey website I found their contact page -
you guessed it: no contact information, but you can leave a message.

Try leaving the folks a "help help" message, ask not just what the green light means but ask for a service and installation manual for your pump, and keep us posted on how things develop.

Question: sharing a well with different types of pressure tanks and different home elevations

(Sept 25, 2014) David said:
question: are their potential problems with two homes connected to a domestic well when one home is connected at the bladder pressure tank, and the second home (uphill from the well) is connected at the well?



Issues may arise with whose water pressure is controlling the pump.


(Oct 24, 2014) Tim E said:
What is between well and house and looks like a dumbell?


Other than me when I'm poking around, I'm not sure. Send me a photo and perhaps we can answer more usefully.

Question: relationship between pump on time and faucet pressure

(Jan 27, 2015) Anonymous said:
On the pressure switch there are 2 adjustment nuts. the small one allows the pump to run longer. can allowing the pump to run longer help regulate the pressure coming out of the faucets? our pressure weakens until the pump kicks on.



Your statement of the role of the 2 adjustment nuts on the pressure control switch is not quite correct. But you can read exhausting details about how each nut works, which way to turn it, and how the large and small nut adjustments interact -

In More Reading above see the article titled


The smaller nut on most controls adjusts the differential - the gap in pressure between cut-in and cut-out. Making this gap smaller will turn the pump on sooner when you are using water.

Question: changing a pump from 120V to 240V

(Jan 28, 2015) Anonymous said:
will i get more gallons per minute out of a shallow well pump if i hook it up to 220 v instead of 110 v?


No but you may work the pump less hard, see a longer life, and perhaps a different electric bill if your pump is capable of being switched to 220V.



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