Shallow Well Jet Pump-Not drawing water-low pressure

[matt4irish]

Appreciate any help! We have a lake cottage with a very old F&W single line (suction) jet pump. Always drain the pump and household lines for the winter and have always been able to prime and go in the spring.

Not this year. The cold split the main supply line in the crawlspace, so we had to replace. Once we did, we can prime the pump and get it to build some pressure (24psi), but it keeps running on and on never coming close to the 40psi cutoff pressure.

When I open a faucet, we are just getting a lot of air and very little water. Left open for more than a few seconds the pressure falls out to zero and then I have to reprime the pump.

The well is outside the crawl and an iron pipe comes into the crawl. From there 1" PE pipe connects to galvanized with a check valve just before the suction port of the pump. I can feel cold water in the suction line about two feet below the check valve, but no cold water past the check valve at the suction or discharge side of the pump.

The gauge showing the slow build to 24psi when the pump is run is on the discharge side, between the pump and the tank. This pressure has held for at least 12 hours without dropping.

Leads me to believe the system is sealed from air leaks at least from the check valve through the pump and throughout household plumbing.

What are the possible culprits?

I'm leaning toward:

1) Possible issue with check valve not opening far enough to allow sufficient water to flow into suction part of the pump.

2) Clogged inlet/venturi of jet pump

3) Old jet pump simply not able to create enough suction to lift water all the way.

Are these reasonable assumptions or anything else to consider? How would you recommend proceeding?

 

[Valveman]

24 PSI is about what you get when the jet nozzle is clogged. Might run a wire through and see what happens.

 

[Sponsor]

 

[matt4irish]

24 PSI is about what you get when the jet nozzle is clogged. Might run a wire through and see what happens.

I did try to do that last night. Took the large nut off the end of the bullet and ran a coat hanger into the hole. Its in a hard spot to see, but didn't seem to have an effect. I can definitely try it again. Is that the correct way to do so?

 

[Valveman]

Should be a plug just under the suction pipe. Wire hanger should do it. If the jet is clear the pump may just be worn out. But you could still have a suction leak and they will let air in but not water out.

 

[matt4irish]

Should be a plug just under the suction pipe. Wire hanger should do it. If the jet is clear the pump may just be worn out. But you could still have a suction leak and they will let air in but not water out.

I know I am in the right plug and I can see the end of the nozzle

 

[matt4irish]

Is there a reliable way to test if it is sucking air in with sufficient volume as to not pick up or sufficiently elevate the water column?

 

[Reach4]

Is there a reliable way to test if it is sucking air in with sufficient volume as to not pick up or sufficiently elevate the water column?

Do you get air in your water?

Also, use the search box above to look up

 

[Midriller]

Vacuum gauge will tell you how much suction you have. What brand of pump is it?

 

[matt4irish]

It's a very old K&W bullet style pump. The company guessed it was probably from the 1970s. Amazing it lasted this long, they made a bullet proof pump especially considering the water in this area. I ended up cleaning again with no further success. Decided to put a new pump in.

Interestingly when I replumbed for the new pump, I noticed the check valve was not smooth and may have been stuck. Would a stuck check valve give similar results (pump runs and runs, can't deliver much water, but will pressurize the output side to maybe 25PSI (which is essentially all air pressure)? Only asking as I'm trying to decide whether to keep the old pump or discard. Thanks!

 

[Reach4]

nterestingly when I replumbed for the new pump, I noticed the check valve was not smooth and may have been stuck. Would a stuck check valve give similar results (pump runs and runs, can't deliver much water, but will pressurize the output side to maybe 25PSI (which is essentially all air pressure)?

No. The symptom of a check valve stuck open would be cycling.

What did (which is essentially all air pressure) mean?

 

[matt4irish]

But, what if the valve was stuck closed as it seemed to be when I pulled the pump?

 

[Reach4]

But, what if the valve was stuck closed as it seemed to be when I pulled the pump?

Then you don't get flow (gpm) through the pump.

 

[matt4irish]

Of course you dont get flow, but would the pump potentially build to say 24psi by pressurizing air downstream?

 

[Reach4]

When I open a faucet, we are just getting a lot of air and very little water. Left open for more than a few seconds the pressure falls out to zero and then I have to reprime the pump.

You get a low flow of water and and a flow of air. Air can only come from the water level being below the intake or a vacuum leak. A check valve stuck open or closed cannot introduce air.

If the pump were pumping only air, the air would need to come in somewhere.

 

[matt4irish]

That definitely makes sense. Thanks!

 

[Midriller]

If your tank is precharged to 28 or 38 psi it's not uncommon for the water in your pump to make some pressure against a tank/closed valve. I often plumb a throttle valve on the output side of the pump for diagnostics. Sometimes you can tap on the check to get it to free up and open. I'm assuming you meant F&W, and yeah theyake great pumps, they are what I install every day, also if you were getting air, the pump would loose prime and could not make any pressure

 

[matt4irish]

Meant to update sooner. It was a failing pump. Picked up a replacement 1/2 hp jet pump and plumbed in and water pressure rose to 55PSI with good volume. Thanks for all the help.