Pump psi drops from 45 to 20 instantly

[Nowell Dunwell]

Bought a house with a well, that's 150' deep, about 50' from the house. House is on a slab and has been "remodeled" numerous times by questionable means and I'm now redoing everything.

From what I can tell, the main water pipe that comes from the well, T's off somewhere UNDER the slab. One end comes up in a closet, where all the main water pipes (bathroom, kitchen, laundry) are located. Water softener, filter, and pressure tank are in there too. The other end that gets T'd off, apparently feeds the spigot that runs outside. I haven't found where it feeds up from the slab yet, but suspect it's behind/under/in a previous outside wall that's part of a porch now.

Everything (pipe-wise) in the closet was just replaced starting at the main pipe in the floor going up. So, it immediately T's off to the pressure tank, then filter/softener, and water heater; cold T's off to kitchen/bathroom/laundry while hot goes to each as well.

I have a ball valve right at the main pipe on the floor, and few other ones at certain points downstream too. If I close a valve after the pressure tank, I can pressurize the system w/o having anything else on (kitchen, bathroom, etc.) however the outside spigot is still on the line and it is affected by the pressurized tank.

So, for simplicity's sake, I shut the valve AFTER the pressure tank but the water line is still pressurized for the spigot. I go outside, and turn the spigot on from a 45 psi static pressure i.e. everything has been off for awhile. Water pressure starts at 45psi and runs good for about 30 seconds roughly. WHEN the pressure switch clicks, the pressure gauge shows it abruptly dropping to 18-20 psi. Outside spigot reflects the drop by less flow. If I leave it running, it'll eventually build pressure back up.

Tank and pressure switch appear newer (probably within last 5 years) although the house sat for 2 years, unoccupied, and suffered at least the first winter with water in the pipes and there was numerous cracks in the copper. I cleaned up the flow of the pipes (50 years worth of newer/older stuff cobbled together) and ran new everything, however the "T" for the switch and pressure gauge were untouched.

I've run the well 24 hours to clear it (water is clear) and even power washed the siding all day Saturday. Only issue so far is that drastic drop in pressure when the switch opens. If not using water, the system stays at 45 psi though it's crept to 48psi a few times.

Hopefully that makes sense?

 

[Nowell Dunwell]

Here's a pic of what's been done with the pipes. Use a zoom feature to look closer. Water heater is directly behind the wall behind the tank/filter. Inlet from slab is lower right corner area nearest the tank. Don't mind the mess, it's rough atm.

 

[Sponsor]

 

[Valveman]

I would invest in a new pressure gauge. The pressure should not stay at 45 or creep up to 48. The pressure switch should turn the pump on at 30 and off at 50, or on at 40 and off at 60. A delay in water delivery after or when the pump starts can be caused by having too much air charge in the tank. it could also be a bad diaphragm in the tank and it has water on the air side, which isn't good. A delay could also be from a bad check valve down on the pump. But you won't really know what is going on until you can see the pressure switch turning the pump on and off at the correct pressures.

 

[Nowell Dunwell]

If I drain the tank, and with it empty, check pressure? If there is a diaphragm leak/tear, I assume the air would escape with the water when draining?

I'll look into a new switch while at it.

 

[Reach4]

Water pressure starts at 45psi and runs good for about 30 seconds roughly.

1. What is the water pressure just before the pressure drops quickly? That would represent the current air precharge.
2. How long before the pressure drops precipitously does the pressure switch click? I would expect it to appear instantaneous.
3. How long is the pressure low?

My thinking might be to raise the water pressure rather than reducing the air pressure. I would turn the nut on the big spring CW a bit. 3.5 turns is about 10 psi increase on both the cut-in and cut-out pressures. So maybe go up a quarter turn or half turn.

 

[Nowell Dunwell]

^ That seemed to work. I went ahead and increased (tightened) the larger nut and slightly increased the smaller nut. Opening faucets and going back to watch the gauge, it'll eventually turn the pump on at about 30 and hold 30, then build up vs. before where it'd drop when the pump came on.

Thanks!

 

[Reach4]

slightly increased the smaller nut.

I would undo the change made to the nut on the smaller spring. Clockwise on that increases the differential (usually 20 psi). The nut on the big spring changes both cut-in and cut-out.

 

[Nowell Dunwell]

Looks like there were 2 different issues. One being the settings which after changing, stopped the drastic drop in pressure when the switch clicks. Other being it looks like the switch is also faulty. It's been gradually dropping to the mid/lower 40's as a shut off. Pressure isn't leaking out as it'll hold whatever the switch cuts at, but the switch's cut is not consistent.

Thanks again guys for the advice.