Pump Not Reaching Shutoff Pressure

I recently installed a new 1/2 hp shallow well jet pump with a 42 gallon air bladder tank pressured at 18 psi. There is a water tank under my driveway that is approximately 6' x 8' and 7' deep. I think it holds 2000 gallons of water. The pump is installed on the driveway surface, so the approximate depth of the pump to the bottom of the tank is less than 10 feet.

The system ran correctly for 1 month. That is, it would run the pump until the pressure guage reached 38 psi, then it would cut off. And it would turn on when the pressure went below 20 psi.

I am re-plumbing the house, so after I installed the system, I left it turned off unless I needed water. This meant it was started approximately 10 times per week for the first month.

Now, it has a problem: it will not reach the 38 psi cut off. It pumps up from 0 psi to 18-22 psi "normally" but then it just keeps running with no more increase in pressure.

It can hold this 20 psi pressure at least overnight.

So I changed the foot valve, hoping this was the problem. There was some sediment (very small rocks/sand) in the pipe that fell out when the foot valve was removed, but I was not the one who removed it, so I only heard about it, I did not see how much. The tank was cleaned prior to the pump installation, but it was pretty dirty before then.

I re-primed the pump, and the pressure reached 10 psi then stopped, so I drained the house water pressure, and re-primed the pump. This time it reached 18 psi. So I repeated the process, and it reached 22 psi. Repeating the process would not increase this pressure any more.

To my ear, the pump still sounds normal with no clattering or other troubling noises.

I am certain that the water level in the tank is about 6" above the foot valve. But this also means that there is only 1 foot of water in the tank.

I have read some troubleshooting guides on the Internet, but none seem to address this problem.

Since the pressure holds overnight, can I assume that there are no leaks in the system?

The last things that I can imagine are that there is still air in the suction line, the water level is too low, or there is a problem with the pump (impeller?) which may have resulted from the sediment.

Can anyone give me some advice?

Update On This Problem

Here's an update:

Today I filled the tank, and that made no difference, the pump will still not reach the shutoff pressure. I removed the pressure guage to be sure that there was no air in the system. It did get to 25 psi, which is higher than before.

Today I also listened closely to the pump sound as the pressure increased. It takes about 15-20 seconds for the pressure to go from 0 to 15 psi, then the pressure rate of increase slows down around 18-20 psi, and takes 60 seconds to reach 24 psi.

This time I noticed a "whooshing" or "swooshing" sound that I did not hear as the pump went from 0 to 15-20 psi. The sound was not constant, but cycled 1-2 seconds on, 1-2 seconds off.


Anyone recognize these symptoms?

I would say you have several problems. The first sounds like crud in the impeller and/or jet.

The second, the whooshing sound and the cycling sounds like your footvalve is stuck open.

What brand pump and tank?

Did this pump ever do any better than 38 PSI, or is that just where it shut off?

bob...

Thanks for your response

Hi Bob,

I would say you have several problems. The first sounds like crud in the impeller and/or jet.

How do I determine if this is true, and what is the fix?

The second, the whooshing sound and the cycling sounds like your footvalve is stuck open.

I installed a new foot valve (even though the old one looked OK) and I have a classic configuration with the pressure guage as the highest point, and the pump mounted on a vertical tank. When I remove the pressure guage, there is water to the top of the pipe. When the foot valve was removed, the water drained out and I then had to prime the pump. If the foot valve was open, wouldn't the water drain out each time the guage is removed?

This whooshing sound is subtle - it's not a sound that stands out from the normal pump sound very much. I'm one of those people who hears noises in cars, motors, etc., that other people usually do not hear.

The pump is not cycling. When I power the pump on, it will stay on forever trying to reach the cutoff, but it can't, so I have to remove power so as not to burn out the motor.

What brand pump and tank?

This pump is at my 2nd house in Mexico, and I think it is a 1/2 hp "J-Series" pump. I purchased the pre-assembled pump w/tank in Mexico, and I was told the pump is a Jacuzzi product. It is mounted on a 42 gallon Flotec(?) bladder tank (I think that's the brand). I can not find any reference to this J-Series pump on the internet, and the hardware store where I bought the unit could only provide me with a different pumps user manual. Today I will go to the other house and write down the info on my pump and tank and post it tonight.

Did this pump ever do any better than 38 PSI, or is that just where it shut off?

It has a 20/40 psi non-ajustable pressure switch - so, assuming some error in the pressure guage, 38 psi is the shut off. As I said, for the first month, the pump could make it to the cutoff pressure easily (in like 30 seconds).

Thanks again for your help,

Lloyd

I'm not fond of the brands you described. Especially a Jacuzzi with a non adjustable switch.

To check the impeller you will have to take the pump apart and look into the eye of the impeller for trash.

If you installed a new footvalve and your hearing a whooshing sound, I would think water is going somewhere. If you have a main valve, shut it off. See if the pump will make anymore pressure than before. Maybe you have a stuck toilet. If the pump isn't shutting off it's not the footvalve because the water would be going toward the house not the well.

bob...

Take Pump Apart

Thanks again Bob,

Are you talking about the removing 4 large bolts that hold the portion of the pump where the suction pipe enters? Is there anything I need to be careful of when removing this assembly? Will this void my warranty?

I did try closing the main to the house and seeing if it made a difference - but it had no effect.

Lloyd.

If your worried about a warranty, take it back now. It's not working right. The problem is, if it is trash in the pump, that would not be covered by most warranties.

I assume there would be 4 bolts holding the two halves together. I won't work on them so I am not real sure.

bob...

Goulds makes a J series jetpump. In fact, alot of Goulds JRS pumps are in use in Mexico. The JRS is Goulds' cheaper jetpump.
I concur with Speedbump, that the impeller and/or ejector nozzle is plugged up. Find out what pump it is. Some pumps have nozzlres that can be cleaned out without taking the pump apart.
Ron

I Got the Pump Name Wrong

The pump is a Franklin Pump J-Class Cyclone Series 1/2 hp shown at this link:

http://www.franklinpumps.com/JetPumpsInfo.asp?brandid=JC&catSectionid=70

It says it has a "Self cleaning, anti-clogging injector screen" whatever that means.

Guess I will go check with retailer to see what he says about this.

Thanks for the advice,

Lloyd.

I know Franklin Motor Corp. bought out Jacuzzi Pump Co. But I'm sorry to see they are selling junk. And that's what any plastic pressure pump is in my opinion.

You might do better with a pump made of cast iron.

bob...