Water or well pump pressure control switch FAQs set #6

This article series answers commonly-asked questions about  how to adjust a well pump or water pump pressure control switch. We provide pump pressure setting advice, procedures & questions & answers about adjusting the pump switch.

How to set pump pressure switch cut-in / cut-out pressures Q&A-6

These questions were posted originally at WATER PRESSURE CONTROL SWITCH ADJUSTMENTS - be sure to review the instructions given there.

[Click to enlarge any image]

Watch out: SAFETY WARNING OF FATAL SHOCK HAZARD: if you remove the cover of the pump pressure control switch you can get access to the two nuts that adjust the operating pressures of the water pump.

• DIFFERENT WATER PRESSURES for DIFFERENT BUILDING AREAS
• LIGHTNING STRIKE PUMP PROBLEMS
• LOST WATER PRESSURE
• PRESSURE SWITCH CLICKING SOUND
• PRESSURE SWITCH CONTROL PANEL
• PRESSURE SWITCH HUMMING SOUND

 

Should I be using a 30-50 psi switch when running 38-64 psi cut-in/cut-out?

Should I change the air pre-charge pressure in the water tank?

I have a 20 gal wellxtrol with a 30-50 psi squareD Pumptrol switch with pressure reading that are unusual. The pressure switch needed replacing because contacts were sticking. I put in a new pressure gauge and measured before I replaced the switch: tank pressure 18 psi, cut in 42 psi, cut out 67 psi. The system seems to work fine. It's 25 years old.

I replaced the switch with the same, and adjusted it to 38 psi cut in, 64 psi cut out. Do I need to increase the tank pressure to 36 psi? Should I be using a 30-50 psi switch when running 38-64 psi cutin-cutout? - D. Hurry

Reply: The 30-50 psi pressure control switch is acceptable. Set the water pressure tank air pre-charge to 2 psi below the cut-in pressure

D Hurry:

First, if your present pressure control switch is handling your (somewhat high) setting of 38/64 psi cut-in/cut-out you don't need to change the switch itself. Square D's pressure control switches typically can handle pressures up to 220 psi - much higher than a typical residential water pressure tank setting will ever be.

In the article above we list the factory air pre-charge settings for models of Well-x-Trol water pressure tanks.

Please read the WARNINGS about messing with tank air pre-charge in the

article WATER PRESSURE CONTROL SWITCH ADJUSTMENTS

Then you can set your pre-charge pressure (with all water drained out of the tank) to 2 psi below the cut-in pressure on your pressure switch, or as you suggested, for a 38 psi cut-in, you'd set the air charge to 36 psi.

That 4 psi difference, however, is not very significant. Leaving the tank at factory pressure and setting the pressure control switch to a higher cut-in/cut-out pressure means that the volume of water you can draw from the tank before the pump turns on is a bit reduced.

Details about how to adjust the water pressure control switch are at different pressure ranges?

I just had a well switch replaced but now I have low water pressure. The pressure switch is set for 20/40 pressure and I know that the previous switch was set to 20/50 psi on and off.

The plumber says the swich is pre-set and that's it! But looking at your website I see that one can re-set the pressure switch.

I am 60 yrs old and a widow and will try to do this myself as i saw your info on tightening a nut inside that gray box that the plumber put on.

What i want to know is that one CAN change the pressure on any and all pressure switch boxes? or is it true you have to order anther box preset for the pressures i had? ALSO i have a blue water tank with a bladder - how much pressure will be too much? - E.S., Louiville KY 10/14/2013

Reply:

When the plumber said the switch is pre-set to 20/40, s/he's right that that's how the switch came from the factory

But most pressure switches permit a limited range of adjustment or fine tuning. We discuss this in the article above.

But again, one does not usually need to mess with the pressure settings, and often, as I elaborate below, often when we're not satisfied with "water pressure" we ought to be checking for obstructions that reduce the water flow rate before just blithely upping the pressure settings.

Typically a 20/40 psi switch could be set up to a 50 psi cutoff and work OK, but if you set the pressure higher than your pump can reach the pump will just keep running;

Watch out: I would not set the pressure over 50 in any case; both to protect the pump and to avoid overpressurizing the tank.

Details are

at WATER PRESSURE TOO HIGH: DANGERS.

Also let's be sure we're talking really about pressure, not water flow rate. Pressure is measured as a static condition - how much pressure is in the system when water is not running.

Water pressure alone does not make for great flow rate at the plumbing fixtures.

Picture trying to push 70 psi water (measured with the pump off at the end of a pump-on cycle) through a pinhole-sized opening at a clogged faucet opening. You're still not going to see much water pouring out of the faucet.

When you open a faucet, what people loosely call pressure is properly called flow rate - how much water comes out of the faucet per minute. Indeed upping the pressure switch setting increases the flow rate, up to a point.

But if you are not satisfied with flow rate, other factors should be checked, such as clogged faucet strainers (common especially after work has been done on a plumbing system as we may have stirred up debris); and clogged piping due to mineral deposits (usually first detected in hot water lines).

For some tips also

see WATER PIPE CLOG DIAGNOSIS.

Question: now many turns of the adjustment nut make how much change on a pressure switch?

(Sept 22, 2014) Anonymous said:
Pete how much turning in degrees of the pressure spring nut are we taking about. approx.

Reply:

Anon

Try a 1/2 rotation to one full rotation of the nut you are changing, then observe the pressure response change in the system.

This is not lab-grade precise equipment nor are the effects of adjustment nut rotation degrees consistent throughout the adjustment range.

Question: warnings about limits of the smaller pressure switch nut adjustment range

7 March 2015 Andy said:

Near the top of thisWATER PRESSURE CONTROL SWITCH ADJUSTMENTS article, it says: 'Watch out! If you loosen this nut too much you can set the cut-off pressure below the cut-on pressure and the pump will turn on and run forever (or until it burns up.)'

This doesn't make sense. If you back the differential nut off 'too much', all that means is that the differential will be at its minimum which might cause short cycling. shortcycling is of course damaging too, but the pump can't fail to shut off if the main spring is set anywhere near the standard and all other things are normal. What am I not getting here?

Reply:

Thank you Andy, you're right and we're deleting the confusing text. We appreciate your careful eye and can use all the editing help we can get.

After adjusting nut #2, the smaller nut that in most of these controls adjusts the differential between cut-in and cut-out we kept this warning

Watch out: After adjusting nut#2 you may need to check the actual operating water pressures in your system and adjust nut#1 to be sure that you are not pushing the cut-out (upper pressure) so high that the water pump never turns off (dangerous).

As your comment points out, an additional caveat could be added: don't set the differential between cut-in and cut-out too close or the pump will short-cycle.

A different error would be to set the Nut #1, the larger adjustment, cut-out pressure too high.

That's a common mistake that some folks make in trying to get the highest water pressure possible in their building. The result could indeed be a pump that never shuts off and that burns up.

Question: I'd like to get the cut-on at 60 and cut-off at 70 to get very high water pressure

I just rebuilt a Sta-Rite water pump (JBMG-41S)(2hp). It had never been serviced and had alot of iron build-up. The shaft had seized.

After cleaning it out and putting new seals, it was still able to run ok so I reinstalled it. Then it seemed there was a problem with the pressure switch. I cleaned out the pipes connecting to it and cleaned the switch itself but I wasn't able to get to a setting that wasn't cycling too quickly.

I then looked at the air pressure in the pressure tank.

This system is installed in an old 6 floor apartment building. The city supply is about 45psi I wanted to get a cut-on pressure of about 55psi and a cut-off at about 75.

The pressure tank (Challenger pc266r - 85 gallon) turned out to be over-charged. I'm not sure what the pressure was at but it was over 60psi. I let out the air until it got to around 51.

Now, cut-on pressure was around 55 and the pump was staying on for around 10 minutes before it reached 70psi but even with the differential nut unscrewed all the way I couldn't get the pump to turn off at 75psi. I finally unscrewed the main nut and the pump went off but now the cut-on pressure was slightly lower.

I'd like to get the cut-on at 60 and cut-off at 70.

Help appreciated. - Ben 4/9/12

Reply: watch out: setting the differential too small causes short cycling & setting the cut-out too high may exceed the pump's capacity, burning it up

Ben, please take another look at the details in the articleWATER PRESSURE CONTROL SWITCH ADJUSTMENTS about adjusting the pump pressure control switch.

You'll see that the two adjustments (on switches that have two) do not operate independently, so changing one can require fine tuning the other. The larger nut shifts the whole cut-in/cut-out pressure range up or down, while the smaller nut changes the width of that range - the differential between cut in and cut out.

Question: I want to control water supply to different areas of our factory through Inverter drives

I want to control water supply to different areas of our factory through Inverter drives , pressure feedback in order to simultanously achieve energy saving,equal pump running hours(There are 3 pumps with common header).

There shall be bumpless transfer of pumps so that there is min. pressure surge. Can anyone give me solution - Mehboob Akber 5/21/11

Reply:

Mehbob,

I'm not sure what inverter drives you are talking about, but for general water pressure control to set different water pressures in different building areas,

and provided that the base water supply and delivery system has adequate pressure and flow capacity, you would need individual pressure control tanks, pumps and switches, or for a simpler arrangement, simply a pressure regulator installed at the inlet to each factory area.

 

Pressure Control Switch Noises: Buzzing, Clicking, Humming

Question: humming water pressure pump control switch

My water Pump Pressure Switch seems to be emitting a low hum all of the time It sounds sort of like you hear around electrical transformers. This is a new thing for the unit. My electric bill has also been high and my water pressure is intermittently low.

I can make the hum stop by pressing on the plate that's connected to the springs. It sparks when I do this. Yikes! I suspect that the switch is stuck in the on position. What do you all think? Thanks! - James 11/27/12

Reply:

James, the pressure control switch might click on and off, but humming?

First - make sure that the sound is coming from the switch itself and not from nearby water piping or from a nearby pump. Well pumps are not silent, and pump noise can be transmitted via water piping.

Second - if you are convinced it's the switch, if tightening the electrical connections at the switch doesn't fix it (do this with power OFF) I would replace it promptly.

The pump relay is an electromagnetic switch. If it is humming and vibrating it is probably failing and you're about to have

• a short circuit, maybe a switch burn-up or worse
• no water

span class="RedText">Watch Out: I wouldn't keep pressing on the relay. There's live 120V or 240V in that switch - touching exposed wires or connectors is asking for a potentially fatal shock. Keep me posted, what we learn will help other readers.

See the diagnosis & repair advice at WATER PUMP PRESSURE SWITCH NOISES - what causes humming or clicking noises at a building water pressure control switch: diagnosis, warnings, advice.

Also see WATER PUMP NOISE FAQs for some diagnostic questions and answers for noises traced to the well pump, pump controls, or water tank.

Question: after replacing pump and pressure tank the pump switch keeps clicking

relay switch on water pressure device clicking when water is being used why and what is the fix please. - Anon 9/30/12

i replace my pump and pressure tank. but when i turn on my water. i here the pressure switch go click click click non stop when i turn on water - Jerry 11/16/12

Reply:

Jerry,

Watch Out: If the clicking pressure switch is switching the pump on and off very rapidly, say every second, TURN THE PUMP CIRCUIT OFF immediately to avoid damaging the equipment. Then check for a clogged water filter, a water valve that should be open is closed, or a waterlogged preside tank

Anon:

It is normal for the relay switch to "click" on and off when you are running water continuously.

It's a sound that folks don't notice if the switch is right next to a (noisy) well pump, but when the well pump is submersible (located in the well) the pressure control switch click may be about all you hear.

If the clicking is rapid - see my warning just above. If the click occurs say once every 30 seconds, that's normal. It's the pump switching on and off as pressure falls and rises.

Water Pressure Control Switch or Control Panel Diagnosis

Question: pump control panel overload message

(Feb 17, 2015) jeevan said:
in my control panel it is displayed over load

Reply:

Check the instruction manual for your pump control for details. Most likely you're being told that the pump is drawing excessive current, indicating a short, wiring failure, failing pump impeller or bearings, or clogged intake screen.

Lost Water Pressure FAQs: water pressure slowly falls to zero or stops completely, returns, or does not return later

Question: lost water pressure, came back on its own, plumber replaced presure switch.

I had a Plummer come to my house on the week-end since I had lost pressure for my water. When the plumber arrived the pressure was restored but since the system was 21 years old, I decided to have him replace the switch. If I remember I had a 20-40 pressure switch that was adjusted to 40-55 so that when taking a shower we would not notice the low pressure.

When the plumber installed the new pressure switch 30-50 I asked him to adjust the pressure and that is what he did. He adjusted the pressure with the bigger nut as explained in the WEB site, so now the cut-in pressure is about 32 and the cut out is about 58-60.

The problem is that when someone is taking a shower the cut-in rating is to low so the pressure is down. What steps can be done to increase the cut-in pressure but keeping to cut-out pressure to about 60….

So I could have something like 42-60 or so if possible. Thank you - Andre 10/25/11

Reply:

Andre:

Please take a look at the pressure switch adjustment information in the article above.

You'll see there are two adjusting nuts in the control. Basically the larger nut shifts the whole operating pressure range (cut in and cut out) up or down while the smaller nut adjusts the differential between the cut in and cut out.

You can adjust the smaller nut to narrow the differential if you like - just don't make the cut-in too close to the cut-out or your pump may turn on and off too often and overheat.

Question: lost water pressure in freezing weather

(Feb 22, 2015) Cindy said:
how do I know if my lose of water is my pump pressure switch or my pipes are frozen?

Reply:

Cindy,

see WELL WATER PRESSURE DIAGNOSIS

Because is number of failures all result in no water.

In general, if the system was working and then stopped during very cold weather it's natural to suspect frozen piping. Turn off the pump to reduce the chances of riuining it.

If the pump is above ground you can determine that it's running by inspection. If its in the well some electrical tests can do the same.

Question: lost water while watering the garden

I just moved into an old farm house I was watering my garden when I lost water, I had run it for some time. did I use up all the water?

I went to the pump imediatly and turn off the water spicket. did I burn up the pump, I don't get great pressure in the house since I moved in.

later I got a little water but then it was gone again. what can i do to find out what happened - Sandra 6/5/11

Bladder tank set at 30 psi switch set at 40 psi cut off. I have water but no pressure. help - Charlie C 6/7/11

Reply:

Sandra:

You need a well flow test or an approximation of one so that you have an idea just what your well can deliver. If the well flow rate or recovery rate is limited you can drill a new well (expensive, no guarantee of success) or add a larger quantity of water storage in tanks.

But be sure you've accurately diagnosed the poor flow rate; poor water pressure or flow can be caused by clogged piping, for example, or you may have both problems: clogged pipes and a low-flow-rate well. - DF

Charlie:

if you have no water pressure at all I think you may best take a look at the diagnostic guide in theWATER PUMP DIAGNOSTIC TABLE

No water and no pump working following a power failure

moved to WATER PUMP WON'T START

Lightning Strike Effects on Pump & Pump Switch

moved to LIGHTNING STRIKE PUMP PROBLEMS

...

Continue reading at WATER PRESSURE CONTROL SWITCH ADJUSTMENTS - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see WATER PUMP PRESSURE CONTROL ADJUST FAQs7 - more-recent questions & answers about setting the pressure control switch adjustment

Or see these

Water Pressure Control Switch Articles

• WATER PUMP PRESSURE CONTROL SWITCH - home
• WATER PUMP PRESSURE SWITCH INSTALL / REPLACE
• WATER PUMP PRESSURE SWITCH LOCATION
• WATER PUMP PRESSURE SWITCH MANUALS
• WATER PUMP SHORT CYCLING - home
• WATER PUMP PRESSURE SWITCH SAFETY

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WATER PUMP PRESSURE CONTROL ADJUST FAQs-6 at Ins pectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER SUPPLY, PUMPS TANKS WELLS

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