Well Pressure switch

[TimPicard]

Thanks to those who've replied before, and I am sorry I haven't resolved the fact my pump runs often and briefly.

Wellwater switch (at base of tank) switches on at 25 psi, and off at about 32. The pressure tank reads 32 psi.

I screw the cut-off switch down, but almost no increase in cut-off pressure.

The switch is 20/40.

I think the tank should be two pounds less than the cut-off, so should I increase the pressure in the tank to 38?

Bad switch? Clogged pipe?

Thanks, everyone!

 

[Reach4]

Why do you think your pressure tank is not shot? https://terrylove.com/forums/index.php?threads/well-water-pressure-switch.90911/

Precharge is always measured and set with the water pressure =0.

 

[Sponsor]

 

[Storm rider]

I think the tank should be two pounds less than the cut-off, so should I increase the pressure in the tank to 38?

It should be 2 pounds less that the cut-on, so if the cut-on is 25 the tank pressure should be 23. That should be measured when there is no pressure on the system.

 

[TimPicard]

Why do you think your pressure tank is not shot? https://terrylove.com/forums/index.php?threads/well-water-pressure-switch.90911/

Precharge is always measured and set with the water pressure =0.

Frankly, I'd bet the tank is OK and I messed up! I am confident that my adjustments screwed up the pressure, more than any mechanical failure, but of course could be wrong. I'm the type of knucklehead who'll adjust first to see what happens ...

As it is now, the pump starts at 25, off at 32. Tank reads 32 PSI, but I know I released some air a while ago (I'm an idiot, as I stated.)

So, shut off power, shut off line after gauge, empty water, check tank pressure, set to 18 (because gauge is 20/40?), then turn on power and see what the gauge reads?

Hopefully tank doesn't read zero ... ?

 

[Sarg]

I just went through much the same frustrations as I replaced my water heater & pressure tank last week. I also screwed up the settings on my original Square D switch. Some things I learned from the group here:
The pressure switches are all the same .... they are just preset at the factory different i.e. 20/40 - 30/50 - 40/60.
The large spring will move the "range" ......... so you could change a 30/50 setting to a 35/55 setting or whatever........... Also it is best NOT to touch the settings on the small spring . It only changes the ceiling or top setting and once you mess with it the original setting is VERY hard to get back. Do not mess with it.
Your switch demonstrates 7 psi range ? That shows you messed with the small spring ...... Go buy a new one. They are not expensive ... I bought several 30/50 's just to have back-ups when the points start to fail. I also found that the 1/4 nipple the switch is mounted on was almost totally clogged .... if your system has been in service for awhile plan on getting a new one .... easier and more efficient than trying to clean out the old one.
Your pressure tank must be 2 to 5 pounds LOWER than your start pressure. I found out after screwing around for several days that the bladder in my old tank had a leak causing erratic operation that you won't be able to understand. I did not realize the tank was shot until I removed it and could hear water sloshing around above the internal bladder. If your system components have been in service for a long time best to ponder replacing them & saving yourself a lot of headaches. The pressure tank is CRITICAL for consistent operation.

And another lesson I learned the hard way .... when assembling use 5 or 6 wraps of the .0035 pro Teflon tape PLUS pipe dope ( sealant) on top of that. No fun chasing leaks.

 

[Reach4]

Hopefully tank doesn't read zero ... ?

When the water pressure is higher than the precharge pressure, the air pressure will read about the same as the water pressure. That can be useful to check to compare calibrations on your water pressure and air pressure gauges.

The small difference is a sum of altitude effects, and possible tension in the diaphragm.

When the water pressure is zero, the tank should be empty of water. It will be relatively light. In some tanks, you can tell by knocking near the bottom with water in the tank vs no water.

Maybe show us a photo that includes the pressure switch, pressure gauge, pipe coming from the well, and the input to the pressure tank.

 

[TimPicard]

When the water pressure is higher than the precharge pressure, the air pressure will read about the same as the water pressure. That can be useful to check to compare calibrations on your water pressure and air pressure gauges.

The small difference is a sum of altitude effects, and possible tension in the diaphragm.

When the water pressure is zero, the tank should be empty of water. It will be relatively light. In some tanks, you can tell by knocking near the bottom with water in the tank vs no water.

Maybe show us a photo that includes the pressure switch, pressure gauge, pipe coming from the well, and the input to the pressure tank.

See set-up in picture.

Tapping on tank, sounds like it's 2/3 full. Also states it's 28 psi, and my air pressure gauge reads 29, so likely as it should be.

Unless you guys suggest something else, I'll drain and check pressures.

 

[Reach4]

Tapping on tank, sounds like it's 2/3 full.

Now repeat that with the water pressure=zero.

With your picture, I can see that you don't have one problem that some people have.

I forget; have you changed the pressure switch during your troubleshooting?

 

[TimPicard]

I have (mal)adjusted the switch, but NOT replaced. Contacts look dark, but nothing else apparent.

 

[Reach4]

I have (mal)adjusted the switch, but NOT replaced. Contacts look dark, but nothing else apparent.

If you don't find retained water in your tank, changing the pressure switch is cheap and easy.

Another test for the pressure tank is to bring the water pressure to zero. Measure the air pressure. Wait for a few hours, or overnight. If the pressure drops and the temperature has not, the tank is bad.

Or if there is water retained in the tank, the pressure tank also indicates a bad pressure tank. Click Inbox, above.

 

[TimPicard]

Water drained from tank, but as you can see in the picture, gauge still reads (stuck?) about 21 psi. And ... tank now reads zero.

Power is off, line to home is closed.

Bad gauge, bad tank?

Our house in more than 20 years old.

 

[Valveman]

Get a new gauge, check the air in the tank, then start over with your tests.

 

[TimPicard]

Get a new gauge, check the air in the tank, then start over with your tests.

So, even though the tank reads zero (had read ~29 before I drained it), tank might not be bad?

Should that bladder area have ~28 psi?

 

[Sarg]

Just observations >>>> You state the pressure tank sounds 2/3 full. be aware a 20 gallon tank holds 5 gallons of water ... so the 25% capacity applies .... e.g. a tank rated at 40 gallon holds about 10....... sounds like your tank has a internal leak & you have water above the bladder. Now if your tank is empty and you do the "tone" test. If it sounds like there's still water inside the bladder has definitely leaked.
And the gauge is bad.

 

[Reach4]

Get a new gauge. Liquid-filled is nice. I don't have one, but I plan to get one if I ever replace my pressure gauge. Some premium price, but not bad.

Check to see if tank is empty with open drain (ensures zero water pressure). If water in it get pressure tank too. Do I seem repetitive?

Get a new pressure switch too? They are cheap (under $20 maybe), and it might be convenient to order at the same time. On the other hand, your prior observations about water pressure based on the gauge don't mean anything.

Click Inbox above.

 

[TimPicard]

Thanks, y'all. I hope you know how much your advice is valued!

I'll stop by a close and reputable plumbing supply house tomorrow and pick up a gauge and switch.

So, my current is 20/40, OK to replace with 30/50?

 

[Reach4]

So, my current is 20/40, OK to replace with 30/50?

Probably. To use a 30/50 switch, you would probably want the pump to be able to pump to 55 psi or more.

You can turn a 30/50 switch up or down.

 

[Bannerman]

You said you were adjusting the tank pressure while the system was pressurized. Letting too much air out from the tank while pressurized, the space the air occupied will become filled with additional water so the tank will then contain more than only 25% water.

With less air in the tank, not all of the water will have necessarily been pushed out when the water pressure is at the 20 psi pump cut-in pressure. When there is 0 water pressure as confirmed by no flow to an open faucet, the tank precharge pressure maybe 0 psi and some water could remain in the tank even as there may be nothing wrong with the tank.

Turn off the pump and open a faucet and leave it open after the system has drained. If the tank pre-charge reads 0 psi, add air to push out any remaining water from the tank and then add air until the pre-charge is 2 psi below the pump cut-in setting.

If replacing the pressure switch with 30/50, adjust the tank precharge to 28 psi. Leave the pump shut-off for 1 hr and check the pre-charge pressure again to confirm it is holding air. If the 28 psi remains, use the system as usual but check the pre-charge pressure again after 1 week to confirm the tank continues to hold the correct pre-charge.

 

[TimPicard]

I bought a 20/40 switch, but looking at a couple resources for replacing, it appears the wiring on mine differs from others I've researched.

Both black (hot?) on one side, neutral on the other?

 

[Reach4]

That is good. If the pump is a 230 volt pump, the white wires are also hot, rather than neutral. If the pump is a "115 v" pump, the white is neutral.

Convention is that the outside terminals are connected to the wires from the breaker box, and the inside two go toward the well.

Do you want a different test for your pressure tank being failed? If so, identify your pressure tank.