Jet pump won't reach pressure

[phoenixmac]

Hi- Installed a new Goulds J7 in 2020 and things have been running fine until last night (why is it always nights and weekends for this stuff?)

Just before bedtime I noticed the pump was running nonstop and wouldn't build pressure above 38 PSI (pressure switch is set for 30|50).

Turned off the main valve just past the tanks in case there was a leak somewhere and the pump kept running.

Turned off the breaker to the pump, gave it a few seconds and then turned it back on. The pump ran for half a second and then cut off, pressure still at 41 PSI.

If it wouldn't build above 41 PSI, it makes me think maybe air got in somehow.

If it was the pressure switch, I'd think it would just keep building pressure.

Any thoughts on this?

 

[phoenixmac]

Curiouser and curiouser. Checked the pressure switch, it's clean and the tube is clear.

Thought I had it when I checked the backpressure (pressure control valve) and it was wide open (the locking screw had come loose). So with the pump running, I set it to where it had been (about 45°) - and got no increase in pressure. Closed it a little more just to really increase the backpressure even more and still no change.

If I close the main valve downstream from the pump to isolate it, turn the pump off, and watch it for 30 minutes, there's no change in pressure at the pump, so I doubt a leak.

So now I'm stuck with doubting the pump or the injector down the hole. It's a three year old pump so I'm trending on the injector being clogged somehow. I'll probably replace the pressure switch just because that's cheap but I'm not expecting a miracle.

Am I missing anything?

 

[Twowaxhack]

Bump

 

[RS]

I don't think replacing the pressure switch is going to help, they are easy to bypass/troubleshoot. If it mounted on the pump motor, make sure the line going to it is clear, if mounted to the pressure tank T make sure the nipple is clear.

 

[wpns]

Check or replace the pressure guage, they are also cheap and prone to failure or clogging.

I’d also remove the nipple thst leads to the switch and poke around in there with a small screwdriver, mine clogs up with rust in that area occassionally and causes strange issues. Which reminds me, I should do mine again.

But yeah, either impeller or injector if you have no leaks in the suction line.

 

[phoenixmac]

I don't think replacing the pressure switch is going to help, they are easy to bypass/troubleshoot. If it mounted on the pump motor, make sure the line going to it is clear, if mounted to the pressure tank T make sure the nipple is clear.

Thanks. Replacing didn’t change anything.

I did adjust the range on the switch down and also further reduced the cutoff pressure. Adjusted the pressure in the tanks and it’ll at least cut off now

 

[phoenixmac]

Check or replace the pressure guage, they are also cheap and prone to failure or clogging.

I’d also remove the nipple thst leads to the switch and poke around in there with a small screwdriver, mine clogs up with rust in that area occassionally and causes strange issues. Which reminds me, I should do mine again.

But yeah, either impeller or injector if you have no leaks in the suction line.

Yep. That’s where I’m at.

 

[phoenixmac]

Check or replace the pressure guage, they are also cheap and prone to failure or clogging.

I’d also remove the nipple thst leads to the switch and poke around in there with a small screwdriver, mine clogs up with rust in that area occassionally and causes strange issues. Which reminds me, I should do mine again.

But yeah, either impeller or injector if you have no leaks in the suction line.

How could a three-year-old pump have impeller problems?

 

[wpns]

I have no idea, but it is a possible failure mode that might lead to the problem that you are seeing.

You are unlikely to be having the kinds of issues that I see where my pump sucks in leaves and other debris from my rainwater cistern, but anything is possible, and it’s fairly easy to check by pulling the pump housing apart.

Just a thought, and an issue I have seen. If your impeller is cracked or clogged, then it might cause this.

The best part about these forums is the “double your money back” guarantee

 

[Valveman]

Doesn't matter if it was caused by a suction leak, a dry well, or a frozen pipe, but when the pump doesn't/can't shut off the impeller gets hot and melts down, making the problem even worse. My guess is a suction leak, (which won't leak water out). But if you fix the suction leak and the jet nozzle is clear, the impeller being melted could still cause low pressure.

 

[phoenixmac]

Not knowing what a melted impeller looks like, I only notice a small distortion in the center flange and just noticed what looks like a small gap in the rim (at the center bottom of the picture) but is just the edge of the vane.

 

[wpns]

Doesn't look awful, can you remove it and look down the vanes?

 

[Valveman]

That part with the "gap" in the rim is the eye of the impeller. The outside diameter of the impeller eye should fit in the wear ring on the diffuser with only a few thousandths of clearance between the two. When there is too much clearance between the impeller eye and the wear ring the pump looses a lot of efficiency and pressure building capability. It doesn't look very bad, but it doesn't take much.

 

[phoenixmac]

Hi again. Follow this link>> Video on flow and tanks

The saga continues and I'm beginning to believe I have a leak down the hole. But hey, your thoughts are very welcome.

 

[Valveman]

Your pictures and videos are too close. I can't see anything but the gauges. Would like to see how it is set up and what kind of "bypass" valve you are talking about. Also, should really never have a valve on a pressure tank like that.

 

[phoenixmac]

Your pictures and videos are too close. I can't see anything but the gauges. Would like to see how it is set up and what kind of "bypass" valve you are talking about. Also, should really never have a valve on a pressure tank like that.

Except for the ball valves, the fittings on the tanks are what I inherited. I moved the tanks away from the wall (between the pump and the 1-1/4" riser) because I had to repair the wall (not sure if you can tell from the angle but it was a mess. After inspecting the impeller on the new pump (inconclusive), I replaced the new pump with the old one, getting essentially the same results.

The "bypass" is where the hose is attached and the ball valve from the front tank is closed (though the handle broke off). So with the ball valves closed, I "bypass" them by opening the spigot where the hose is attached.

This is an old well with a 6" casing that is severely corroded. If I had to guess, the new 160 PSI HDPE pipe has been rubbing against that and rubbed a hole somehow, but that is pure speculation, If that turns out to be the case though, I'd like to replace the suction line (assuming that's what's at fault) with a sturdier HDPE, perhaps 200 PSI rating or at least something with a greater wall thickness.

Also, why not a ball vale on the tanks?

 

[Valveman]

After looking at your set up and watching the videos I don't think you have a suction leak or a clog in the jet nozzle. I wonder if just restricting the pump a bit more with the back pressure valve on top is all that is needed? That should make it build a little more pressure, which looks like all that is needed.

A leak would cause the pump to come on after a time, even when no one is using water. A clogged jet usually won't build more than 20-30 PSI. A little more back pressure from the back pressure valve might be all that is needed to up the pressure.

If someone closes the valves to the pressure tanks it is bad for the pump, so I normally do not put valves that can shut off the tanks from the system. Removing the handle would be safest, making sure the valve is open all the time.

If more back pressure doesn't fix it, I would look for a partially clogged jet nozzle next.
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[Valveman]

Please let me know what you find. The more I think about it the more I am sure it is a back pressure issue. Never seen it before but I guess that back pressure valve could be bad. It just works like any ball valve, but if it is worn it may not be closing like it looks.

 

[phoenixmac]

Please let me know what you find. The more I think about it the more I am sure it is a back pressure issue. Never seen it before but I guess that back pressure valve could be bad. It just works like any ball valve, but if it is worn it may not be closing like it looks.

Indeed, I did fiddle with the back pressure, but, like Paul Harvey would say:“And now, the REST of the story!”

Pulled the pipe and found that the screen on the foot valve had come off, allowing this nugget(s) (aka: boulder) to block the nozzle. How I was getting any flow at all is a mystery to me!

Thanks again to everyone!