Pressure Switch Chatter

[HereOnThePrimalEdge]

This is a new one for me.
My pressure switch chatters (clicks on & off rapidly).  At first it did it occasionally when the switch/pump engaged, then the pump ran normally.  I cleaned the contacts but now it does this:
* when a small amount of water runs it chatters
* when a large amount of water runs the switch & pump turn on normally, but shut off immediately when I turn off the water

Pressure tank psi is good.  I have a new pressure switch ordered, but wanted to stop the chatter in the meantime before the switch gets here.  Any suggestions?

Added info - it’s a 220 volt well pump system

[oink]

Is the tank waterlogged? Check the air pressure when the tank is empty, if you haven't.

[Obie]

Pressure tank bladder is probably pau.

[HereOnThePrimalEdge]

Is the tank waterlogged?
... 
Pressure tank bladder is probably pau.

The switch is 40/60, the pressure tank is reading is 38 psi.
If I tap on the tank, it’s mostly air.
If the bladder was defective, it wouldn’t hold pressure would it?  Or would fill with water?

[Obie]

Like oink said, you need to drain the water out of the tank and then check the pressure.

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7. Pressure Switch and Pump Continuously Cycles On and Off
This water well problem can be caused by a leak in the home so the well pump is continuously running. It can also be due to corrosion of the water well casing, liner or screen, causing holes. Holes can allow water of undesirable quality to enter the well. Look for leaking toilet flush valves, reverse osmosis systems, iron filters and other backwashing filter systems that may be malfunctioning.

A common cause is a failed check valve. The check valve or foot valve prevents the well pressure tank from sending water back down into the well after it has built up with water pressure.

If the valve fails water streams back down the well and the pressure switch turns the pump on again. This on and off cycle may occur every few minutes and essentially allow the well pump to run practically 24 hours a day, causing a high power bill. Replace the check valve and the problem is solved.

Another very common issue is the pressure tank losing its captive air pressure. This is easy to check. Turn off power to the well pump and run water after the pressure tank or in the house until there is no water pressure left. Using a tire pressure gauge check the Schrader valve on top of the pressure tank. It should be 2 PSI less than the cut-in or lower pressure. If your well turns on at 30 and off at 50 PSI, it should have 28 PSI in it.

[HereOnThePrimalEdge]

Thanks Obie, but I don’t think it’s any of those things.  The pump doesn’t short cycle, I’ve had that happen before.  This is chatter - - the switch turns on & off rapidly, 2 or 3 times per second.  There are no leaks in the system, when the pump gets up to pressure it shuts off, and doesn’t switch back on unless I open a faucet.

[oink]

Have you checked the pressure with the tank empty yet? There should be no water in the tank at that point. Then fill with air as outlined by Obie. If the pressure is way off or the tank is waterlogged it will act as you've described. As mentioned by Obie, a busted bladder will cause it. If the bladder is blown you can limp along for awhile by adding extra air but it won't act like a bladder tank any more. It will reflect it's true size and air will have to be added more often. The larger the tank the better it will work with a busted bladder. Do you have a gauge on your system so you can observe the pressure while it running and cycling?

Good luck.

[HereOnThePrimalEdge]

Thanks oink,
Yes, I turned off the pump, drained the system, and siphoned one connection with a garden hose to a spot 5 feet lower than the pressure tank just to be sure - - the tank still reads 38 psi.  It’s still hollow sounding when tapped.

The new cut in/cut out switch arrived today, so the next sunny day I’ll change that out.

[oink]

Maybe the switch got out of adjustment somehow. Take off the cover. It should tell you how to adjust the cut in/out on the underside of the cover. It's not hard but you will need to be able to see a pressure gauge to do it. All you need besides a gauge is the proper size nut driver. Just don't electrocute yourself. An some of them one nut will control both the cut in/out and the other will just adjust one. So you have to set the one that controls both first and then the other. You can change a 20/40 into a 40/60 or a 15/50 or whatever floats yer boat.

[HereOnThePrimalEdge]

The pressure switch and meter arrived in the mail yesterday.

I first replaced the pressure meter.  The old one seemed like it was working, but I couldn't be sure since the pump cut in and out irregularly.  I didn't know if it was on the high end, low end, or gave an incorrect meter reading.  With a new meter I'd know it was right, and could adjust the pressure switch if necessary.

When I compared the old pressure switch with the new one, I realized the contacts on the old one were unusually far apart.  In the back of my mind I remembered "The Professionals" I hired to install a water meter a few weeks ago had said when they finished "and we adjusted the pressure switch and pressure tank so they were set together properly."

oink: Maybe the switch got out of adjustment somehow.
Yes, maybe when I hired two "Professionals" at $70 an hour so I didn’t have to do the job myself, maybe somehow the switch got out of adjustment?  I reset the switch where I had it in the first place, which also reduced the space between the contacts.  It cuts in exactly where it should, cuts out exactly where it should, and the tank is at the proper psi.  Everything works perfectly.


The chatter was created when "The Professionals" widened the switch gap so far apart, the contacts couldn't click into place properly for a metal to metal connection.  With that slight gap the switch chattered on and off, trying to run, but couldn't continuously. 

Thanks everyone for your help and suggestions.