Plumbing/Pressure Tank Question

[phantom22]

Last week I replaced my pressure tank that had become waterlogged. I have a switch that is for 30/50 lbs. I have set my pressure tank at 28 PSI.

The waterlogged symptoms hav4e gone away, but a new issue has popped up and I don't know if it's a bad switch or something else. When the pressure gets to the low end it almost stops and then slams back on when the pump engages. It will repeat this every few minutes (it's only a 20 gal. pressure tank).

When I watch the gauge with the water running it will shut off at 50 and when it gets down to around 30 it kicks on. There will be a jump of the gauge needle upwards and down and then a smooth rise to 50 to repeat.

It doesn't seem like there is any air left in the line as it isn't hissing at me. Could there be air in a line somewhere else like a water spigot or something or maybe I need to recheck the tank pressure?

I'm sure it's something simple as my plumbing expertise is mostly shark bite fittings and teflon tape. If anyone has any ideas I would appreciate reading them.

I'm savvy with computers and medical stuff if you'd prefer to barter instead. :kidding:

[brokeasajoke]

Odd indeed. My mother-in-laws gauge does this but it is probably 10-15 years old. Possibly a bad gauge and replace with an oil filled gauge?

[lavenatti]

Did you add air to a new tank? I recently installed one and it came pressurized.
Could it be to much air?

[Bmi48219]

It’s been a while since I dealt with pressure tanks. Try setting your tank at 30 psi.

[georgerkahn]

A decade or so back I was advised to install one, so I went to plumbing store, bought one, and soldered it in. However, a bit after it behaved "weirdly" -- not the same as yours, but similar. A seasoned tradesman friend came over and suggested my not being the brightest lamp in the fixture, as I had installed it resting upon an inverted 5-gallon buck on floor. After a bit of teasing me, we un-soldered it and reconfigured with straps, now hanging from (basement) ceiling 2" x 6"s; zero problems since. It makes no sense to me, as there's still two floors worth of toilets and sinks above it -- but Herb suggested raising the tank to be the cure and -- albeit it may be a coincidence (???) -- it seems to have been the fix.
I'm NOOOOO plumber -- but I thought I'd share this.
geo

[Hossfly]

Sounds like combination, bad switch and or nipple under switch almost closed. Easy fix replace both.

[jsizemore]

With all faucets closed, does it hold water pressure on the gauge ? If not, then you need to find the leak which starts at the foot valve and goes throughout the system.

If it holds pressure, what your seeing is normal till you clear all the air out of the water piping. Just go around open all the faucets till there is no remaining air in the lines. I usually open the tub spouts first to reduce stuff in the aerators. Your set pressure for the well tank is correct for 30/50 when there is no pressure on the system.

If none of that clears it up, your tire pressure gauge you used to set the tank pressure is bad.

[Hossfly]

H2O mechanic good to watch on u tube.

[Rapier]

I have a 100 gallon pressure tank and have had this one and several others since 71 in multiple houses that I have designed and built.

My switch and tank itself have pressure setting, both are set at 40-70 on the new house with new plumbing. Older plumbing may require a lower pressure settings. I am also hooked up to a municipal water system with double gate valves and a back flow preventer. The municipal water is a raw feed of 65 PSI constant. As said, new plumbing.

The in and out lines must be air tight, not just water tight.

If you have a two setting system, set at two different pressure levels, this causes a similar problem to what you are reporting. They turn on and off at different times on the same pressure run to a full stop.
If the tank is new, it should have been filled by you, with the main valve at the tank to the house cut off, so the tank does not fill completely, it must compress air in the tank to make pressure on the water, then after it shuts down, you open the tank to house valve. If the pressure tank gets full of water, water logged, simply empty the tank, completely, then start filling it. Most tanks have a bladder, if the bladder gets broken or perforated, 99% of the time the tank itself must be replaced.

Bugs play hell with pressure tank switches, they get into the switch, no contact or spotty contact. Major problems. Older switches have points like auto ignition points, A handy emory board is a good thing to have. Turn off power, circuit breaker, etc. then remove the switch cover and open the spring loaded points, close on emory board, sand both sides of the points flat and even, to make 100% contact. The points develop mounds of electrical burned metal material, mounds must be removed.

You should have a water faucet at the bottom of the pressure tank, turned out towards the pump house door and a short section of garden hose to run the water from the tank to the outside onto the yard or gras.

If you have a septic system, tank, field lines, etc. That is normal for a well fed water source. The septic system is a whole different learning curve.

Red iron is OK if moderate to light, yellow iron or rust stain is not OK.

[243winxb]

Gauges not always correct.

Increase tank pressure 2 pounds.

[phantom22]

Ok so I have more information as I went in the crawlspace and looked at it while water was running. I think it might be a bad switch or pressure gauge or maybe both.

When the pump is on it climbs to 50 PSI and shuts off as you would expect. It goes smoothly until 40 PSI. At that pressure it drops rapidly to 30 PSI and sits there like it's at 0 PSI for a few moments before the pump kicks on and fills back to 50 PSI. Those moments from 40-30 PSI and the few moments it rests there is when there is no water pressure.

I noticed all of this when I was trying to run every spigot open at the same time to purge any air (didn't notice any) and was watching the gauge. It seemed like the easiest first attempt to see if it helped, but I wanted to report my findings before going further.

[metricmonkeywrench]

Not sure if you have a in well or jet pump system. There’s a balancing act between the tank pressure and the switch, assuming all the components are good. Take a look at the pressure on the bladder side of the tank without any water pressure on it. If I remember correctly the goal is to have the pump come back on just before the pressure drops to the lowest set point. This does two things, keeps some head pressure on the foot valve and acts as a shock absorber when the pump kicks on. Usually in the tank instructions or on a sticker on the side is the recommended bladder pressures for various set points.

Hope this helps..

[waksupi]

I'd had a similar problem, with the pump going on and off constantly. Several plumbers had tried to figure it out with no luck. I had a well man in to replace a switch box, and mentioned the problem to him. He took a quick look, and told me the inlet pipe was undersized. He changed it out in a half hour, charged me much less than a plumber. Problem was gone.
The lesson I learned was call a well man for everything up to and including the pressure tank, and let a plumber deal with other issues.
I currently have a problem with a what I suspect is the pressure tank I had put in a few years ago, so the plumber who installed it is coming to check it out this next week. The old pressure tank lived for over 30 years, so I hope this is still on warranty.

[jsizemore]

It's not uncommon in the winter months for a bit of crud/rust to build up in the nipple that supplies the water pressure to the contactor and pressure gauge. Remove both from the nipple and use a #2 philips screwdriver to poke through the rust/crud. Turn the contactor over to make sure there's not any crud in there either. Reapply teflon tape and wiring. Energize the circuit. You only need to go around and open each faucet individually to clear any air in the lines.

[chambers]

Correct procedure to set tank pressure is to remove all water pressure from tank( open water valve), set pressure to 2 psig less than cut in pressure. If your cut in is 30 psig, then tank pressure is 28 psig. May want to also change your water pressure gauge to help set up for accuracy. Use two different tire pressure gauges to check correct pressure on tank for accuracy.

[white eagle]

I leave that to the pro's
my tank got a pin hole in it and was spraying water everywhere
had to replace unit

[.429&H110]

Whatever the pressure switch cut-in is set for, the tank has to be 2# less.

The joker in the deck could be the pressure switch is full of rust and turning on late.
They don't last forever and wear out, there's an ugly diaphragm in there.
(Is that how you spell diaphram? Go figure...)

[jimlj]

Last week I replaced my pressure tank that had become waterlogged. I have a switch that is for 30/50 lbs. I have set my pressure tank at 28 PSI.



maybe I need to recheck the tank pressure?

You have the tank set correctly IF the gauge you checked the tank pressure with is correct, and the pressure switch is actually turning the pump on at 30 PSI. It sounds to me like you still have too much air pressure in the tank. 1, shut off power to your pump. 2, run water till the tank is empty and no water is flowing. 3, lower the air pressure in the tank another 2 PSI. 4, turn the power back on to your pump and see if the problem is fixed. If the problem is gone but you feel like the water flow in the house drops too much adjust the pressure switch so it turns the pump on sooner, IE adjust to 35-55 PSI start/stop.

[oley55]

I had the OP's problem after installing a new pressure switch (one with the power cut-off lever). Bought another new switch without the power cut-off lever and life was good again.

[trapper9260]

Correct procedure to set tank pressure is to remove all water pressure from tank( open water valve), set pressure to 2 psig less than cut in pressure. If your cut in is 30 psig, then tank pressure is 28 psig. May want to also change your water pressure gauge to help set up for accuracy. Use two different tire pressure gauges to check correct pressure on tank for accuracy.

This is all correct .I use to work for some well companies and for the tanks that have no bladder in them. You need to drain the tank first. Normally you pump air in it to get all the water out . Then you do what chambers stated. Also you can get some water from a tank with no bladder as to the one that have it once you get the water out you out of water. Also at times the pressure switch has gone bad that need to be changed. When a bladder tank if the switch keep going on and off . Just change the switch. If the bladder breaks that is very seldom it will be a pain to drain and move around .

[phantom22]

Been off the computer for a while. I appreciate everyone taking the time to help. If you guessed too high of pressure in the tank you are the winner. Went and drained off all of the pressure and it read 40 PSI!!!!! Back her off to 28 PSI for real this time and it fixed the issue.

Thanks to everyone again!

[Woodtroll]

Good news! Follow-ups are always appreciated on curiosities like this. Thanks for the update.