Low pressure before pump kicks in

severtki · Aug 16, 2006

We have a shallow jet pump with a captive air tank system (40/60psi). We get very low water pressure (dribbles) while I watch the pressure guage run down toward 40. When it reaches 40, the pump kicks on and we have great pressure (though the guage reads near 75psi when it kicks off -- higher than the 60 the pump is set for).

Sounds like a pressure switch, right? If so, then the pressure guage on top of the pump must have coincidentally gone, too, since it reads 40psi when the pump kicks in.

Or would some kind of blockage somewhere cause these problems (before I start ripping in and replacing parts)?

Thanks in advance,
Kirk

Rancher · Aug 16, 2006

How fast does it run up to 75? Sounds like you may have a waterlogged tank.

Rancher

Sponsor · 2022-01-29T12:20:58-0800

severtki · Aug 16, 2006

Pump runs for about 30 secs.

Seems strange that if it's waterlogged, that both the pressure gauges would be reading wrong, though, doesn't it? That would be three separate parts failing within a couple months. (Bladder, pressure gauge, and pressure switch).

Worth it to drain and check pressure as a first step?

Speedbump · Aug 16, 2006

You would have to worked that pressure switch pretty good to get a 40 / 75 setting.

Do you have any sort of filtration?

bob...

severtki · Aug 16, 2006

Haven't touched anything -- it was running 40/60 about 6 mos ago last I checked...

Household filtration system is after both pump and tank -- regular cartridge-type filter.

I don't believe it's actually going up to 75 psi -- I think I'd notice a difference from the regular 60psi we're used to...

Bob NH · Aug 16, 2006

You could have air pressure at empty tank that is greater than the start pressure, or the pump could be slow to provide water if it is getting an air bubble in it.

You can test it with the pump power off. Slowly drain water from the tank while watching the pressure switch and the gauge. The switch should actuate ON while there is still pressure on the gauge. Then, it should drop another couple of psi before suddenly dropping to zero. That is when the tank is empty of water.

If the gauge suddenly drops to zero and the switch closes at the same time, you have too much air in the tank.

If there is an air leak that gets air in the pump so it is slow to come to pressure, or if you have a check valve between the pump and the tank and the foot valve is leaking, you can get slow pressure response when the pump starts.

You can give it a little more time to start by lowering the air pressure another 2 psi. However, that will also shorten the cycle time.

severtki · Aug 17, 2006

That's funny -- I've never seen the pressure suddenly drop when draining the tank. It always goes slowly down to the last trickle.

I drained the tank last night and pressure was around 20psi for the air -- so seems like a low air problem. Only had a bicycle pump handy so will look today for an air tank to borrow and will see if that clears it up.

I still don't understand though -- if it's just low air, wouldn't that cause the pump to cycle more often? What we're getting from the faucets when gauges are at 50psi is nothing like what 50 psi should be...

Gauge on the pump reads consistently 10-15psi higher than tire gauge at the air stem on the tank does. I think it must be hosed in any case...

Thanks for all your help on this thread!

Speedbump · Aug 17, 2006

I think you need some new gauges. You shouldn't be getting different readings that far off.

If you have low pressure issues in the house, try taking the filter out of that rinky dink filter canister.

If you have low air pressure in the tank and it is one with a dome itside, which is supposed to protect the bladder, that would cause the pressure to spike to higher than normal pressure when the bag hits the top. That may be the reason for the 40/75 setting.

bob...

Bob NH · Aug 17, 2006

"We get very low water pressure (dribbles) while I watch the pressure guage run down toward 40. When it reaches 40, the pump kicks on and we have great pressure (though the guage reads near 75psi when it kicks off -- higher than the 60 the pump is set for)."

It is possible that you have a failed bladder that is partially blocking the outlet of the tank. Or there could be some other blockage that prevents the tank from discharging. That would explain why you get only a trickle when the pump is off, but good flow when the pump comes on.

A piece of junk such as a piece of bladder between the tank and the line could be getting trapped in a valve or something when it tries to flow out of the tank, but is displaced when it flows into the tank. If the tank is connected with a union, you might take the union off and run the pump to try to clear the line to the tank.

Raucina · Aug 19, 2006

I have seen the sears bladders act as a flexible floating and or sinking disc when broken, which sort of works as a check valve. water in , little water out - then sealed again. Dependant on air pressure in the tank all kind of weird things happen. Designers, manufacturers, and sellers of tanks with "bags" as bladders should feel the sting of the lash across their pitiful shoulders.

severtki · Aug 19, 2006

Fixed!

Thanks to everyone for their responses. I finally determined that the bladder was ruptured and the air tank was waterlogged. That caused a whole series of cascading problems -- including blockage of the household water filter with debris from the disintigrating bladder.

I bought a new tank yesterday, installed it, and flushed the lines. Everything is working great now!!! I was happy because I didn't have to call anyone in to help.

Raucina · Aug 19, 2006

hope you bought a glasslined tank and CSV

Moral of the story: People burdened with bladder tanks need banks of 1 micron filters before any point of critical use

Speedbump · Aug 21, 2006

Just curious, what brand of tank did you buy?

severtki · Aug 22, 2006

To my chagrin, it was a Flotec. The only one I could locate in our area.

Speedbump · Aug 23, 2006

Be prepared to buy another one in a year or so.

bob...

severtki · Aug 23, 2006

I'm holding on to the 5-year warranty paperwork... it was an easy enough job, I wouldn't mind doing it again... https://terrylove.com/forums/images/smilies/wink.gif

Low pressure before pump kicks in

Users who are viewing this thread

severtki

New Member

Rancher

Guest

Sponsor

Paid Advertisement

severtki

New Member

Speedbump

Active Member

severtki

New Member

Bob NH

In the Trades

severtki

New Member

Speedbump

Active Member

Bob NH

In the Trades

Raucina

New Member

severtki

New Member

Raucina

New Member

Speedbump

Active Member

severtki

New Member

Speedbump

Active Member

severtki

New Member

Similar threads