Pressure Drops To Zero When Pump Turns On

[cknick]

I am wondering if this could be the result of some interesting/incorrect plumbing of my shallow well jet pump. I will be trying a new pressure switch but I have an interesting pipe that runs from the outlet side of the pump back to the inlet side of the pump before the check valve. There is a valve on that pipe and it has been open since we bought the house 2 years ago. I haven't tried closing it. I figured someone put it in for a reason but I can't figure out what that might be. Any ideas? It's the blue pex pipe in the photos.

 

[Reach4]

I assume that the photo with the PVC elbow is your well. I think you have a "single pipe" deep well jet pump. The blue pipe would carry water through the adapter on top of your well, down your casing, to the venturi/ejector that drives water up the center pipe. The leathers are a seal. The foot valve is a check valve with a strainer, so you would normally not have another check valve if I am correct.

Is this valve you refer to in one of your photos?

 

[Sponsor]

 

[cknick]

I don't think that is the well. There is a well outside the house a few feet from the foundation where the pump is. I'm guessing the connection with the PVC drops below the frost line then over to the well. I think the greenish looking thing attached to the other side of the PVC is a check valve. So to me it looks like that check valve is pointless if there is water running back behind it from the outlet side.

 

[LLigetfa]

There is a well outside the house a few feet from the foundation where the pump is.

This is confusing since the first pic shows what looks to be a pump. Are you saying you have two pumps?

 

[Bannerman]

The blue line appears to be causing water to flow in a loop from the pump outlet to the pump inlet. Unless there is a check-valve/footvalve below where the blue line Ts into the well line, water will continue to exit the pressure tank and will be forced by pressure into the well.

Close the ball valve to determine if the system will retain pressure when the pump is not running, and to ensure the pump will continue to operate as intended.

I suspect that line was likely intended to prime the pump when some water remained present in the pressure tank.

 

[cknick]

I figured out that my pressure tank was set at 22 psi and the cut on pressure was 20. I lowered the pressure and that solved my problem. I turned the ball valve off and it didn't seem to have any effect on the system. They must have done if for some reason and you might be right about keeping it primed.

As you can see, my pump is pretty old. I also have to crawl all the way across a crawl space to get to it. I'm considering changing to a submersible pump and putting the pressure tank in a utility closet upstairs. I know I will need to run power outside but is there any other considerations before I start that project? My well casing appears to be 3" so I will need a 2" submersible. Do those work well or should I just stick to a jet pump?

Thanks For the Help.

 

[Reach4]

The reason the air precharge was higher than the cut-in may be that the person needed to reduce the pressure switch setting because the pump was not reaching cutoff, and forgot to adjust the air precharge. It could also be that the person's water pressure gauge and air pressure gauge were calibrated differently.

My well casing appears to be 3" so I will need a 2" submersible.

3-inch ID (3.5 inch OD) schedule 40 PVC? You can put a "3-inch" SQ pump into that. They are actually 2.9 inch.

I don't think there is a 2 inch submersible suitable for a water well.