Submersible well pump went out, thoughts?

[rangerfredbob]

Without going crazy I could only check one leg of the motor with my amp clamp (making reasonable assumptions they "should" be the same...) but it was only 3.6A so it's probably a little low which would make sense with the low pressure... I imagine the motor is fine just the pump is eroded from all the sand it's digested over the last 8 years...

 

[Fuddyduddy1952]

One thing you might check is the small pipe going from pressure tank to pressure switch.
They can clog and cause problems.

 

[rangerfredbob]

If it had a high pressure or didn't turn on I'd look there but my system has two gauges that both read 30psi with the pump running constantly so the pump can't make pressure. I'd so much rather it be that little pipe

 

[Fuddyduddy1952]

Yours is acting exactly like mine did before I replaced pump. The pump ran longer, light stayed on...I set pressure lower just to get by but eventually replaced pump. The first pump in the 1980s pipe was galvanized and I pulled by hand. That was a job! The second replacement I pulled pump, I used 1" black plastic so a lot easier but pump was fine, the torque twisting broke a wire through. I replaced pump anyway, gave old good pump to a needy family. I put a torque arrestor on the new pump.

 

[etpm]

A few months ago I had to have my approximately 25 year old Grundfos pump replaced. The pressure dropped from about 80 PSI to zero. Pulling the pump the problem was obvious, the splines on the motor shaft had stripped. I believe the reason this happened was because the 4 nuts that held the motor to the pump were missing. The only thing holding the motor to the pump was the wires.
Looking at the old pump I could see quite a bit of wear so the pump itself would have probably started delivering lower pressure pretty soon. But it was still delivering plenty until the splines stripped. This is because the pump is a centrifugal pump and the way these pumps work, because they are not positive displacement pumps, they will deliver the same pressure as long as the proper RPM is used and the proper volume is not exceeded. As the pump wears it will still be able to deliver the proper pressure but at a lower volume.
If a centrifugal pump is pumping unrestricted the pressure will be very low, basically atmospheric. When restricted then the pressure can build. So if your pump is delivering water into a pipe that has a big hole in it before the pressure gage the pressure will never get very high. Or, if the pump is spinning too slow the pressure will be low. Or, if the pump impellers are very worn away or leaking internally from wear the pressure will be low.
If you pump suddenly stopped being able to deliver high pressure then I would suspect a big leak or low pump RPM. So if you can't find a leak then suspect low pump RPM. The sudden loss of pressure, and from your original post it seems that is what happened, makes me think that you either have a big leak or that the pump is not spinning fast enough. If the pressure loss was gradual then it would seem that the impellers are very worn.
Eric

 

[repete]

If it had a high pressure or didn't turn on I'd look there but my system has two gauges that both read 30psi with the pump running constantly so the pump can't make pressure. I'd so much rather it be that little pipe

Most submersible pumps (every one I have put in) have check valves to stop water from flowing back through the pump. If you hold pressures of 30PSI at the gauges when the pump is off, I think you can rule out a leak in the pipe.

 

[SPYDERLK]

The water pressure dropped sometime last week so I finally looked into it today and the pressure tank is fine, pressure switch is fine but it would only get to 30psi and the pump was running constant so I went further up the line and found a piece of teflon in the flow restrictor, thought it was from the check valve, nope... I do have a sand problem (or did for a few years after I moved in) so the pump apparently can't make pressure anymore and lost a part of it... I bought the house in '14 and the well was put in the year before that so it isn't that old, the well is around 100' deep if memory serves. I lowered the pressure switch setpoint so it turns off at 30psi and on at 20 so it's at least not running constantly anymore...

So, I know I gotta get a new pump, current is a 3/4hp 4" 3 wire unit since it has a control box and I checked and it has 3 wires plus ground... Home Depot has a pump for $479, Lowes has one for $469, Amazon has them for $200 on up... Which way would you go?

If it was installed in '13 is it likely iron pipe or plastic? The roof panel on the pump house is easy to get off so I'm not worried about that. I didn't think of pulling the cap off the tube when I had the check valve off...

Check and see if the pump is running overly frequently even at the lower pressure. It may be that you have a split in the, probably poly plastic, well pipe. These sometimes develop over time immediately above the pump and would explain excess running and limited pressure.

 

[5030]

Just call my well driller and have him replace it. We have a Red Jacket commercial pump btw.

 

[QRTRHRS]

Pulled and replaced many a pump over the years. Anyone else remember the 1 1/4" steel pipe in 20' sections?

O' yes. I was part of a crew that pulled 400 feet of galvanized with a backhoe and a clamp to keep the pipe from dropping as we unscrewed each section. Great stuff!

 

[QRTRHRS]

If not in already, a sediment filter will help your home's valves, etc. In regards to that sand.