Irrigation Pump

[Tim Beck]

I just purchased a home with an in-ground irrigation system. I noticed an unusual plumbing setup and can't make much sense of it. The water main (city water) enters the basement below ground on the north side, and I can follow the copper pipes to a spigot outside the north wall.

On the south side of the basement, there is a 240v motor and pump that supplies the irrigation system via PVC pipe and is activated by means of a pressure switch. The pump is fed from a large copper pipe that protrudes from the concrete floor of the basement, and is not connected at any point to the incoming water main that supplies the rest of the house.

What is going on here? I've only ever had well water, so I don't know much about city setups. It doesn't seem proper that such a large supply of water would seemingly not be metered and billed to me. The home was inspected and the inspector noted that the basement sump pump discharged into the city sewer pipes, which is apparently typically against code, but he said nothing of the sprinkler pump. Did someone do something shady in the past? Is the water metered elsewhere? Is the city unconcerned about it because the water discharges into the lawn, rather than back into the sewer system where it needs to be treated?

Any help would be appreciated, as I'm hesitant to ask the water department and find that it's a violation and might result in a fine or costly corrections. Thanks in advance.

 

[Tim Beck]

Incoming city water main:

Sprinkler pump and motor:

 

[Sponsor]

 

[JerryR]

To me it looks like your irrigation system is connected to a well, not city water.

Not unusual to irrigate with well water but feed the house with city water.

 

[Tim Beck]

To me it looks like your irrigation system is connected to a well, not city water.

Not unusual to irrigate with well water but feed the house with city water.

That makes sense. I've never heard of wells with above ground pumps, though but I'm not very knowledgeable about plumbing.

 

[Tim Beck]

What is the purpose of the blue water tank? It has to only one fitting, rather than an inlet and outlet, and it is plumbed into the output line of the pump. Is it simply to act as a cushion so the pump doesn't kick on and off at the slightest change in pressure? I have noticed that the pump will occasionally kick on for a few seconds, leading me to believe that there is a parasitic loss somewhere. There is also no backflow preventer on the pump that I can see, though that shouldn't really matter since it is apparently a well.

 

[Reach4]

The pump is fed from a large copper pipe that protrudes from the concrete floor of the basement, and is not connected at any point to the incoming water main that supplies the rest of the house.

The pipe is almost certainly steel. Steel is attracted by a magnet.

What is the purpose of the blue water tank? It has to only one fitting, rather than an inlet and outlet, and it is plumbed into the output line of the pump. Is it simply to act as a cushion so the pump doesn't kick on and off at the slightest change in pressure? I have noticed that the pump will occasionally kick on for a few seconds, leading me to believe that there is a parasitic loss somewhere.

The pressure tank does pretty much what you said. You need a pressure tank if you have a pressure switch. Your air precharge should be set to about 5 psi below the cut-in pressure.

There is also no backflow preventer on the pump that I can see, though that shouldn't really matter since it is apparently a well.

That brass thing near the tee from the well is a a check-valve.

 

[JerryR]

The blue tank is a pressure tank. Do a google search for pressure tank. It acts as pressure storage. It it recharged with air and It had a bladder to separate air and water.

Here’s a picture of a above ground well pump setup. It has 2 pumps. One pumps water from well to a storage tank. The other pumps water from storage tank through carbon filter and water softener to the house. Each pump has a pressure tank.the pressure tanks are white in this picture. The blue tanks contains chlorine that is used in the storage tank.

 

[Tim Beck]

The pipe is almost certainly steel. Steel is attracted by a magnet.

You are right, it's ferrous. In the light, it looked like tarnished copper.

That brass thing near the tee from the well is a a check-valve.

I thought that was just a coupling. How do they function? Is it a spring-loaded check valve?

 

[Tim Beck]

The blue tank is a pressure tank. Do a google search for pressure tank. It acts as pressure storage. It it recharged with air and It had a bladder to separate air and water.

Here’s a picture of a above ground well pump setup. It has 2 pumps. One pumps water from well to a storage tank. The other pumps water from storage tank through carbon filter and water softener to the house. Each pump has a pressure tank.the pressure tanks are white in this picture. The blue tanks contains chlorine that is used in the storage tank.

That's good info. I've never seen a setup quite like that before. All my well water homes had a buried pump that supplied a tank, which then fed a softener before branching off to water heater, etc.

 

[Reach4]

I thought that was just a coupling. How do they function? Is it a spring-loaded check valve?

Yes.

 

[Valveman]

What is the purpose of the blue water tank? It has to only one fitting, rather than an inlet and outlet, and it is plumbed into the output line of the pump. Is it simply to act as a cushion so the pump doesn't kick on and off at the slightest change in pressure? I have noticed that the pump will occasionally kick on for a few seconds, leading me to believe that there is a parasitic loss somewhere. There is also no backflow preventer on the pump that I can see, though that shouldn't really matter since it is apparently a well.

 

[Tim Beck]

Thanks, that's a great aid.

 

[Tim Beck]

What are typical pressures for well pumps? I'll have to double check when I get home, but I think I remember the pump only building about 25 psi. I was filling my pool with a garden hose plumbed the to pump, and it did not have much pressure, even with the spigot fully open.

 

[Valveman]

40/60 is the most common pressure switch setting. 25 is pretty low. The pump is probably cycling on and off while you are running the garden hose, which is not good for the pump and is why the hose pressure is weak.

 

[Reach4]

What are typical pressures for well pumps? I'll have to double check when I get home, but I think I remember the pump only building about 25 psi. I was filling my pool with a garden hose plumbed the to pump, and it did not have much pressure, even with the spigot fully open.

Well pumps come in various forms. Common are submersible pumps down the well, and various forms of jet pump. For this purpose, let's first assume you have a jet pump. Then two possibilities come to mind:

1. A pump has a characteristic curve that describes the pressure (in feet of water or PSI) vs the flow. Suppose you have an SNC-HF pump. 26 psi is 60 ft of head. Suppose your hose was putting out 6 or 7 gpm. You would get about 25 psi on a perfect operating pump.
2. Suppose you had an SNE pump putting out maybe 6 or 7 gpm, but it has a clogged jet. The pump would not develop its normal pressure.

A submersible pump also has a pump curve. You could still show low pressure if the flow is large. To test the pump's pressure producing ability, you would restrict the flow to maybe 3 gpm. Maybe even restrict it to 0 gpm for 30 seconds.

A submersible pump could be sized to deliver low psi. Filling a pool does not take much in the way of psi. Operating a water sprinkler takes psi.

 

[Tim Beck]

40/60 is the most common pressure switch setting. 25 is pretty low. The pump is probably cycling on and off while you are running the garden hose, which is not good for the pump and is why the hose pressure is weak.

It kicks on immediately and remains on the whole time. It does the same when the irrigation activates. I will check again tonight, but I believe the pressure was remaining steady at around 25 psi with little fluctuation.

 

[Valveman]

If the pump comes on instantly the tank is bad. If is just stays at 25 with one faucet on, the jet nozzle in the pump maybe clogged or the pump is bad.

 

[Tim Beck]

Well pumps come in various forms. Common are submersible pumps down the well, and various forms of jet pump. For this purpose, let's first assume you have a jet pump. Then two possibilities come to mind:

1. A pump has a characteristic curve that describes the pressure (in feet of water or PSI) vs the flow. Suppose you have an SNC-HF pump. 26 psi is 60 ft of head. Suppose your hose was putting out 6 or 7 gpm. You would get about 25 psi on a perfect operating pump.
2. Suppose you had an SNE pump putting out maybe 6 or 7 gpm, but it has a clogged jet. The pump would not develop its normal pressure.

A submersible pump also has a pump curve. You could still show low pressure if the flow is large. To test the pump's pressure producing ability, you would restrict the flow to maybe 3 gpm. Maybe even restrict it to 0 gpm for 30 seconds.

A submersible pump could be sized to deliver low psi. Filling a pool does not take much in the way of psi. Operating a water sprinkler takes psi.

It just seemed like a low flow of water for a 5/8" garden hose, compared to the spigot on my previous home. That house had a four or five inch well with a submersible pump, for what it is worth. When I get home tonight I will experiment with limiting flow by only slightly cracking open a valve and see if pressure is affected.

 

[Tim Beck]

If the pump comes on instantly the tank is bad. If is just stays at 25 with one faucet on, the jet nozzle in the pump maybe clogged or the pump is bad.

How would I go about diagnosing these issues?

 

[Valveman]

I'm guessing the pressure switch on that pump works at 30/50. The pump should come on at 30 and off at 50. There should be 25-28 PSI air in the tank with the pump off and no water in the tank. If it builds to 50 and shuts off the jet nozzle is not clogged. If the tank won't hold air or give you 5 gallons before the pump comes on it is most likely bad. You could also have a suction leak. I see several places on the suction where threads or the union could be leaking.