I bought my Parents house with a 8 yr old Well. A year into living there the well stopped running/froze. My Friends and myself pulled the 630' drilled well. We found leaking metal couplings. We replaced all those by cutting the threaded 1' PVC and replacing them with PVC unions. We also replaced the well with a new pump. It worked great for 3 months holding 60psi when the hose was running and getting up to 70 psi when no water was on. Then last night after using the water all day and not having one single problem, the pressure dropped to 20psi.
I worked on it, bleeding all the water in the tank, adjusting the pressure in the tank.

I then listened to the Well via a short piece of pipe into the access hole and could hear water draining into the well. I thought it could be the well re-filling or it could be leaking out of my PVC pipe. So I connected my Air hose to the direct feed faucet on my well house and pumped up the pressure to 75psi and then closed the faucet to hold the pressure. IT HELD perfectly for 15 minutes except I had a small whistle from a coupling at the tank but still held perfectly. Didn't bleed down at all.

So I thought the well could have gone out of water, so I left it all night. This morning almost 8 hrs later it still won't build more than 38psi. I have set the solenoid to run under 38psi so it doesn't continue to run but I can't shower that low or run washer and dishwasher only faucets and toilets. No air bubles so it's constant water in the system.

I need to find out why I can't get anymore pressure. It was running 70psi, now only about 38psi tops.

I am thinking about adding a 10' stick or 2 of PVC to drop the well down further towards the bottom. The well is about 650' deep. BUT I would think there should be plenty of water down there to begin with......

My Dad said they have never gone dry in that well .

The pump is a 2 wire pump 230v. I believe it's 1hp Stainless Steel. No Control Box needed. Run on a Pressure switch.

 

Your original driller/installer did a no-no, and then you followed that with a double no-no.

You probably have sch 80 PVC drop pipe, and should have had either brass or stainless couplings. Sch 120 PVC couplings would be better than galv. When you have galv. couplings in an otherwise inert environment they tend to get rust holes very quickly.

I am hoping you really meant couplings when you said unions. If you did put unions on the drop pipe my guess is that they have separated somewhere. Pull the line out and replace the "unions" with either brass or stainless couplings, and definitely don't glue anything. I'm not saying you can't glue the drop line together, but it's not the best way or recommended way for PVC.

The big problem is that if you've cut off the threads you will have to either re-thread the PVC or get new drop pipe.

 

Sorry for the mis-use of wording. It is PVC couplings.
It's fine to use PVC from what I've seen around the past 3 wells I and my Dad have had installed. One well is 25 yrs old and dried up in 2008 when this one was installed. No adverse affects to having PVC all the way down.

I did replace all the Stainless screw in couplings with PVC. It held 75psi of air pressure when I tested it and as of last night, I am currently holding 78psi of water.

From what I can tell, the well must have just ran low.
I did the depth test yesterday when I got home and found that I have water as high as 120' from the ground level, the well is a total of 645' deep.
I clicked the pressure switch on and it built up to 80psi. I adjusted the pressure switch where it runs 48/78. Been working perfectly all night and morning. I suppose it was just low, that well had never ran low but I guess I put it through it's paces when I got it all back together and over worked the water supply I have.

All is well now.