Need irrigation pump HELP!

[Category6]

Total Newbie. But been lurking for a couple of months.

Our irrigation system was destroyed in hurricane Milton from tree impact. We had a submersible pump at that time. Finding help has been challenging.

Long story short. The pump overheated. The down pipe separated and the pump was stuck. Held up by the wiring.

We were told we would have to remove the fence we had JUST put back up to bring a rig in to drop the pump. We didn’t want to do that if possible.

A colleague said he had an above ground pump. I read here that they are more problematic than a submersible but we were getting desperate as everything was dying from no rain or irrigation.

An irrigation guy with 25 years experience advised us to put in a Gould’s 1.5 hp centrifugal pump. Which he did. We had already determined that the water depth was 42 feet (probably at the level of the old pump), and 14 feet to the surface. He put the down pipe at 35 feet. New piping, wiring, pressure tank, switch.

It ran great. Good pressure. As time goes by, the pump doesn’t stop running. He adjusted the pressure switch. Seems good. Then I’ll hear the pump running. It will run all the zones but then it won’t shut off.

HELP. I’ve asked if the foot valve could be stuck open. He put in a check valve. Which I wondered about. Any ideas? Troubleshooting help? Thanks in advance.

 

[Valveman]

Not a foot valve problem. Check and foot valves only work AFTER the pump shuts off. Most likely the water level has drawn down to a point where a centrifugal cannot lift it. Max lift is about 25'. When water gets deeper than that the pump cannot lift and a deep well jet or submersible pump is needed. Maybe able to lower the switch setting from 30/50 to 20/40 and get the pump to shut off. But if the pump does not shut off when all the taps are closed it will melt the impeller in short order.

 

[Sponsor]

 

[Reach4]

There are ways to replace a submersible pump without a truck-- not that I have done it. One way is with strong hands. up-z-dazy "pul-a-pump" PumpTrax "Easy Riser"

https://www.deanbennettsupply.com/all-products

Could you cut a big-enough gate into your fence for access? Make a removable section?

 

[Bannerman]

Good pressure. As time goes by, the pump doesn’t stop running. He adjusted the pressure switch. Seems good. Then I’ll hear the pump running. It will run all the zones but then it won’t shut off.

If you mean the pump does not shut off while all the zone sprinklers are operating, then that is a good thing.

If you mean the pump does not shut off while no sprinklers are operating and no water is being utilized anywhere, that is a bad thing.

A pump that is repeatedly cycling Off & On, will have a significantly shorter lifespan compared to a pump that operates continually while water is being utilized.

When less water is being utilized than the pump is capable of delivering such as to supply only a few sprinkler heads, then the excess flow will have nowhere to go except into the pressure tank. Once the system pressure rises to the pressure switch Cut-Out pressure, the pump will be shut-down, but continued water usage will cause the system pressure to be reduced again until lowered to the PS Cut-In pressure whereby the pump will be reactivated and the entire cycle will be repeated.

When the water flowing to the sprinklers or other fixtures is equal or greater than the pump's delivery rate, then the pump will continue running non-stop for as long as that amount of water continues to be consumed.

Suggest stating which model of pump is installed, and also describe the configuration of your irrigation system.

 

[Category6]

Not a foot valve problem. Check and foot valves only work AFTER the pump shuts off. Most likely the water level has drawn down to a point where a centrifugal cannot lift it. Max lift is about 25'. When water gets deeper than that the pump cannot lift and a deep well jet or submersible pump is needed. Maybe able to lower the switch setting from 30/50 to 20/40 and get the pump to shut off. But if the pump does not shut off when all the taps are closed it will melt the impeller in short order.

The pump runs the zone/zones with significant pressure. I’ve run one zone. And 5 zones (manually bc I found the pump running). I saw no evidence of weak flow.

Was worried about the depth of the down pipe and questioned it but since it seemed to pull water well, I decided to stay in my lane.

The initial pressure switch was a 30/50. He adjusted it to no avail. Then just replaced it yesterday with a 20/40 commenting that that would 99.8% solve the problem. Nope.

I realize the damage to the pump with overheating. That’s why it stays off unless I’m there to watch it. But that’s not what I paid for.

I’ll NEVER take water access for granted again. And have great admiration for all that keep water in my taps.

 

[Category6]

If you mean the pump does not shut off while all the zone sprinklers are operating, then that is a good thing.

If you mean the pump does not shut off while no sprinklers are operating and no water is being utilized anywhere, that is a bad thing.

A pump that is repeatedly cycling Off & On, will have a significantly shorter lifespan compared to a pump that operates continually while water is being utilized.

When less water is being utilized than the pump is capable of delivering such as to supply only a few sprinkler heads, then the excess flow will have nowhere to go except into the pressure tank. Once the system pressure rises to the pressure switch Cut-Out pressure, the pump will be shut-down, but continued water usage will cause the system pressure to be reduced again until lowered to the PS Cut-In pressure whereby the pump will be reactivated and the entire cycle will be repeated.

When the water flowing to the sprinklers or other fixtures is equal or greater than the pump's delivery rate, then the pump will continue running non-stop for as long as that amount of water continues to be consumed.

Suggest stating which model of pump is installed, and also describe the configuration of your irrigation system.

If you mean the pump does not shut off while all the zone sprinklers are operating, then that is a good thing.

If you mean the pump does not shut off while no sprinklers are operating and no water is being utilized anywhere, that is a bad thing.

A pump that is repeatedly cycling Off & On, will have a significantly shorter lifespan compared to a pump that operates continually while water is being utilized.

When less water is being utilized than the pump is capable of delivering such as to supply only a few sprinkler heads, then the excess flow will have nowhere to go except into the pressure tank. Once the system pressure rises to the pressure switch Cut-Out pressure, the pump will be shut-down, but continued water usage will cause the system pressure to be reduced again until lowered to the PS Cut-In pressure whereby the pump will be reactivated and the entire cycle will be repeated.

When the water flowing to the sprinklers or other fixtures is equal or greater than the pump's delivery rate, then the pump will continue running non-stop for as long as that amount of water continues to be consumed.

Suggest stating which model of pump is installed, and also describe the configuration of your irrigation system.

The pump doesn’t stop AFTER the zone run completes.

The pump is a Gould’s GT-15 Irri-Gator. The pressure tank 20 gallon AO-sept. Factory setting at 25 psi. I asked if the tank needed adjusting due to the 20/40 ps. I was told no.

 

[Category6]

There are ways to replace a submersible pump without a truck-- not that I have done it. One way is with strong hands. up-z-dazy "pul-a-pump" PumpTrax "Easy Riser"

https://www.deanbennettsupply.com/all-products

Could you cut a big-enough gate into your fence for access? Make a removable section?

Multiple attempts were made to pull the pump. MANpower. Block and tackle. Come a longs. The down pipe came right out (50 feet). The wiring was retained until the new above ground was installed.

I had concern about inflow problems with the old pump still stuck. But was grateful to see we appeared to have sufficient flow.

We have a 6 foot gate. SOLIDLY cemented. We were told the rig needed 9 feet. And still needs to clear a tree.

Nothing has been easy post hurricane.

 

[Valveman]

You should have said it was a GT15 to start with. Would have been completely different with a J15S. The GT15 has a max pressure of 50 PSI. When used for suction lift, that decreases with the depth to water. I doubt that pump can even build 40 PSI from that depth, so even a 20/40 switch will be iffy. GT pumps are made to run off pump start relays, not pressure tanks with a pressure switch. A J15S builds a max of 83 PSI and would work well with a pressure switch.

 

[Category6]

You should have said it was a GT15 to start with. Would have been completely different with a J15S. The GT15 has a max pressure of 50 PSI. When used for suction lift, that decreases with the depth to water. I doubt that pump can even build 40 PSI from that depth, so even a 20/40 switch will be iffy. GT pumps are made to run off pump start relays, not pressure tanks with a pressure switch. A J15S builds a max of 83 PSI and would work well with a pressure switch.

Great. I was just told to get a Gould’s 1.5 hp pump.

My specialty is cardiac not plumbing. Plumbing may be harder.

 

[Category6]

The irrigation guy wants to ADD ten more feet of down pipe. Insists we don’t need a jet pump. That we’re just irrigating the lawn, not supplying the house. Things are getting tense.

The next question:
My better half read the pump installation instructions. Said according to it, the pump is too low. That it should be installed ABOVE the casing with a slight slope. Currently, it is BELOW the well cap by about 10 inches with 3 - 90 degree angles to make the connection.

He thinks it might be getting an air lock. Could this be an issue? The pump is about a yard from the well.

Thx again for sharing all your knowledge. It’s frustrating bc we were recommended this guy. He’s not happy either.

 

[Valveman]

Just watering the yard 20/40 will probably be find. Just won't shoot the sprinklers out very far. Also need to adjust the pressure switch so the pump does not cycle on and off when running the smallest "yard waterer". Lol! Might need to shut off at like 42 instead of an even 40.

Air lock or loss of prime can happen if there is a high spot in the suction line. Suction line should be level or incline up to the pump so pump is the high spot in the suction line.

 

[Bannerman]

The pressure tank 20 gallon AO-sept. Factory setting at 25 psi. I asked if the tank needed adjusting due to the 20/40 ps. I was told no.

As Valveman stated, if the pump is incapable of building to 40 psi, the pressure switch (PS) will not be satisfied, and so the PS will continue supplying power to the pump.

What you were told regarding the pressure tank pre-charge pressure is incorrect. When utilizing a pressure tank, the air pre-charge pressure is to be adjusted 2-5 psi LOWER than the pressure switch Cut-In pressure (ie: 15-18 psi for 20/40 pressure switch settings). The lower than cut-in pre-charge pressure, will ensure a small amount of water will remain in the pressure tank, which will continue to maintain positive pressure in the system, even if there is a brief delay for the PS to activate the pump @ 20 psi. With the current 25 psi tank pre-charge, the tank will contain 0 water once there is less than 25 psi in the system, so the system pressure will immediately drop from 25 to 0 psi before the PS can sense 20 psi to cause the pump to be activated as intended.

My specialty is cardiac not plumbing. Plumbing may be harder.

It's all plumbing, just different components utilized for a different application.

 

[Category6]

Banman,
My thoughts EXACTLY regarding the circulatory system and plumbing. I’ve always loved the logic and function. Don’t lose your prime!
(I HAVE been known to use the toilet flush to teach the concept of cardiac output.)

I had my concerns about the pressure tank info. It was written right on the tank, but it was dismissed. Looks like we also need to redo the piping and elevate the pump.What a mess. Will try to find another pump guy.

Thanks for all your help. This irrigation situation is frustrating. But we were supposed to flood. Instead we took the direct hit from Milton but still have our home.

Every so often, it helps to put things in perspective.

 

[Reach4]

Looks like we also need to redo the piping and elevate the pump.

Elevating the pump will not help pressure, I don't think. It could hurt.

Taking out elbows could increase flow.

 

[Category6]

I’ve seen schematics/illustrations of correct pump systems on this site.

Anyone have one showing the correct setup for an above ground centrifugal irrigation pump with pressure tank/switch for use on a shallow well?

What’s the thoughts of trying a cheap (?) submersible, knowing the old pump is still stuck? As of yesterday, the former irrigation guy said he didn’t make contact w the old one at 45 feet.

 

[Category6]

Elevating the pump will not help pressure, I don't think. It could hurt.

Elevating the pump is just an attempt to achieve more linear flow and eliminate the 3 - 90 degree angles from the well cap to the pump.

I mentioned before that the pump was about 10 inches below the well cap. But in reality, including the right angles, it’s probably 18 inches below.

Maybe it’s the least of our problems, but eliminating potential cavitation and air locks seemed like an improvement. It’s probably an irrational hope to appease the pump deities. We’ll see.

 

[Reach4]

OK. With the pump below the level of the well seal. The term "well cap" is usually used for the cap on the casing when you have a pitless adapter -- not that the semantics actually matter.

So when you are measuring pressure, is that while you are irrigating? Or is the pump output only putting water into the pressure tank when you are looking for higher pressure?

 

[Valveman]

A submersible pump would certainly be better. As long as the old pump fell deep enough to set another above it things will work fine. I know of wells where several old pumps were lost and fell to the bottom only to have another set just above it.