Submersible Well Pump Systems
How does a submersible pump work?

OR

6. A separate pump relay switch turns on the submersible well pump as follows:
   
   the well pump pressure control switch senses the pressure drop, closes its internal electrical relay switch to in turn send power to a heavier-duty pump relay switch (usually mounted on a wall near the pressure tank and other water controls). The pump relay switch actually turns on the well pump.
   
   In the submersible well pump photo above you can see extra pump relay switch boxes at the left of the red arrow. The arrow itself points to a submersible well pump that has been removed from the well and left in the utility space that houses a water pressure tank and control that are partly visible in the right side of the photo.
   
   Running a high-amp well pump off of a little pressure control switch will often burn up the switch contacts, or the amperage draw may exceed the rating of the pressure switch itself - that's why the relay switch is used.
   
   See WATER PUMP RELAY SWITCH.
7. The well pump motor runs, drawing water back into the building from the well by "sucking" water up from a shallow depth (a one-line jet pump can't draw water from much below 25 feet)
8. Water is forced into the building water pressure tank and simultaneously into the building piping and on to the plumbing fixtures.
9. If the pump sends water into the building faster than water is flowing out of the open faucet or plumbing fixture,
   
   the pump will "get ahead" of the water flow, successfully pressurizing the water tank, causing the pressure switch to turn off the pump (see step 10 below).
   
   OR
10. If the pump cannot send water into the building faster than water is flowing out of the open faucet or plumbing fixture,
    
    the well pump will run continuously and water will flow out of the open faucet or plumbing fixture at a rate limited basically by the pump's water delivery flow rate in gallons per minute.
    
    You'll also find this condition if a building water supply pipe bursts.
    
    We say "basically" because the well piping and building piping and faucets themselves offer some back-pressure against the pump's flow rate. In this case, the well pump will continue to run until the building faucets or plumbing fixtures are turned off. At that point ...
11. The well pump pressure control switch senses that water pressure has increased to the cut-out point, opening its switch and turning off electrical power to the well pump. The well pump has re-pressurized the building water tank and piping up to the cut-out or cut-off water pressure.
    
    Cut-out pressures are typically set to 40 psi or 50 psi. If you set the cut-out pressure too high the pump may never reach it and will run continuously, or you may find frequent plumbing leaks, or even an unsafe condition, risking bursting a pipe or water pressure tank.
    
    Many submersible well pumps are capable of pumping to high enough pressure to damage the plumbing system or burst a water tank. That's why water pressure tanks need a pressure relief valve installed.
12. The foot valve closes (at the bottom of the well piping) and/or a check valve located in the building on or close to the well pump closes, preventing water and pressure from flowing backwards down into the well, losing building water pressure and possibly losing pump prime
    
    . However because the submersible pump is inside the well at the bottom of the well piping, loss of prime is not a problem directly - that is, the submersible pump, because it is under water, will have no trouble re-starting. But still a bad check valve or foot valve means you may lose building pressure between well pump cycles.
    
    See WELL PIPING FOOT VALVES
    and
    
    see WELL PIPING CHECK VALVES.

Where is the Well Pump?

Take a look at our well casing photograph at above left. See that small gray conduit rising at the left side of the well casing? The conduit carries electrical wires into the well. That's one way to recognize that a submersible pump is installed.

When a water pump is inside the well, it can be tricky to know when the pump is actually on or off, though usually we hear the pump relay clicking, and some relays have a light that indicates that the relay is telling the pump to run.

The pressure switch calls for pumping by switching a relay in the pump relay, that actually turns the pump on and off. So a secondary potential problem would be in the relay itself, but we would look at the pump pressure control switch first.

How to Diagnose Poor Submersible Pump Water Pressure

For our complete water pressure and pump, well, and piping problems diagnostic article list,

see WATER PRESSURE REPAIR GUIDE & COSTS

and see WATER PRESSURE LOSS DIAGNOSIS & REPAIR.

Separately we also provide a WATER PRESSURE PROBLEM DIAGNOSIS TABLE.

The following articles pertain if you have a private well, pump, and tank system for your building or if your incoming community water supply pressure and flow are just too low to start with:

1. Water Tank Problems? 
   
   See WATER PRESSURE TANK REPAIRS. Examples of water tank problems include poor water pressure or the well pump rapidly turning on and off (short cycling).
2. Water pump problems? Examples of water pump problems include poor water pressure or no water pressure at all. See
• WATER PRESSURE CONTROL SWITCH ADJUSTMENTS - poor building water pressure or flow
• PUMP PRESSURE CONTROL REPAIR - pump is not delivering water at all or water pressure is poor
• WATER PUMP RELAY SWITCH - submersible pump has stopped working
• WATER PUMP PRIMING PROCEDURE - well pump keeps losing prime - pump runs but gives no water
• WATER PUMPS & TANKS & WELLS - complete list of articles
• WATER PUMP CONTROLS & SWITCHES - complete list of well pump controls and switches, identification, diagnosis, repair
• WATER PRESSURE GAUGE ACCURACY - maybe water pressure is fine and it's the gauge that's bad?
3. Water piping or well piping problems? If your water pump keeps losing prime, a shallow well jet pump well line could have a bad foot valve
   (in the well WELL PIPING FOOT VALVES) or there may be a bad check valve on well piping at or near the water tank or near the above-ground water pump
   
   (CHECK VALVES, WATER SUPPLY, DRAINS, PUMPS) and so be losing prime. A leak in the well line piping itself can also lead to loss of prime.
4. Well Problems? Do you run out of water or after running water for some interval water pressure and flow are poor?
   
   Well problem diagnosis starts
   
   at WELLS CISTERNS & SPRINGS.
   
   Before assuming that there is no water in the well, check to see if the water pump is working properly, including loss of pump prime
   
   WATER PUMP PRIMING PROCEDURE
   
   and a bad or leaky well piping foot valve
   
   WELL PIPING FOOT VALVES
5. Bad water pump or water tank pressure regulator control? 
   
   See WATER PRESSURE REDUCER / REGULATOR (not usually installed on private well and pump systems, often present on municipal water supply systems that use an in-building local water pump and pressure tank to boost pressure). Water pump pressure regulator switch diagnosis and repair steps include these:
   • How to Adjust Water Pump Pressure: The detailed, step by step procedure for inspecting and adjusting the water pressure control switch is discussed in detail
     
     at WATER PRESSURE CONTROL SWITCH ADJUSTMENTS.
   • Diagnosing Water Pump Short Cycling on and off: If your water pump is clicking on and off too often or quite rapidly
     
     see SHORT CYCLING.
   • Diagnosing Water Pressure Drops without explanation when the pump stops,
     
     see WATER PRESSURE FALLS SLOWLY, ERRATIC PUMP: bad pressure control switch, building water running or leak, bad pressure gauge, bad check valve, bad foot valve.
   • Diagnosing & Repairing Lost Air in the Water Tank: The problem of lost air in the water pressure tank along with how to correct that condition are discussed
     
     beginning at SIGNS OF AIR LOSS.
   • Diagnosing & Repairing a Water Pressure Control or Water Pump Control Switch: We discuss diagnosing and repairing a water pressure control switch that sticks "on" or "off" or simply won't operate,
     
     at WATER PUMP PRESSURE SWITCH REPAIRS
6. Bad Hot Water Pressure? 
   
   See HOT WATER IMPROVEMENT especially if the building cold water pressure is acceptable but hot water pressure and flow are poor. Accumulated debris in a water heater, and debris from a corroded or disintegrating hot water tank dip tube or hot water tank sacrificial anode can also block the hot water outlet opening, resulting in low hot water pressure in a building.
7. Bad cold or hot water pressure and flow just at certain plumbing fixtures? See our discussion of
   
   POOR WATER PRESSURE at JUST SOME FIXTURESust above.
8. Problems with water treatment equipment can cause loss of water pressure or no water flow: a clogged water filter, or a malfunction in water disinfection or other water treatment equipment can cause a reduction in water pressure or even a complete stop in water flow in a building.
   
   See WATER FILTERS, HOME USE for details about clogged filters,
   and
   
   see WATER TREATMENT EQUIPMENT CHOICES for our complete list of types of water treatment equipment.

Reader Comments & Q&A

On 2021-02-05 by (mod)

Thank you for the artesian well questions including the calculation of TDH total dynamic head.

You will see that without knowing specifics of your well such as its bore depth and the height of its water column, nobody can tell you its TDH or Total Dynamic Head.

But please take a look at

TOTAL DYNAMIC HEAD where we explain TDH, repeat your question, and give a very detailed reply.

On 2021-02-05 by Zakaria Hofra

We have a new flowing artesian well, and we want to size the perfect pump for it.
What is the perfect pump (submersible or centrifugal) kind for it?
What is the best depth to install the pump?
How to calculate total dynamic head of the system in such case?

On 2021-01-27 by (mod) - how to prevent the well pipe from freezing

Arthur:

Most well systems keep that pipe between house and well filled with water (unless the foot valve or check valve in the well is leaking or defective)

But some, called "drain-back" systems deliberately drain water back into the well to prevent the pipe from freezing - used where well pipe between house and well isn't below the frost line;

THose are explained at SNIFTER & DRAIN BACK VALVES

On 2021-01-27 by Arthur W Peabody Jr.

My pump is down in the well and piped into the house to the Extrol tank, with the check valve that keeps the house piping charged but on the well side does that line drain back to the well when the pumps shuts down? Might not keep the house heated during the winter from this winter on and need to have the well line empty so it does not freeze?

On 2020-02-19 - by (mod) -

Thank you for the question, Val. I'm not sure I understand the question but I think you're asking

Why would my water pump cycle on and off rapidly for no apparent reason?

If that's the question the answer is at WATER PUMP INTERMITTENT CYCLING

If instead you're asking why the pump cycles very very rapidly on-off at the start or end of a pump-on cycle, then see

CHATTERING RELAY CONTROL SWITCHES

On 2020-02-19 by Val

I have a deep well pump and a 60" water storage tank a pressure switch (probably 30-50) and a Franklin Motor 1HP controller. Researched this site for a while but could not find similar issue discussed. Noticed lower pressure in the house. I can hear (feel) the pump cycle on for several seconds then off for a bit longer, but the pressure switch is engaged. Can't figure out what is causing the pump to cycle? Could it be the controller?

Question: in the summer we run out of water

(June 9, 2012) Jeannie D said:
My question is we have a 160 ft. well and for the past two years in the summer we can't take a shower and
run the air conditioner at the same time. The water presser in the shower comes and goes. We had the well
pump changed in 2010 becuase it quit.

I would love to fix the problem we have company coming but my
husband refuses to have someone check it out and says there is drought. We have water, just can't run two
things at the same time. I say there is something else wrong.
Can you please help.!

Reply:

When your well pump is a submersible unit, as it is inisde the well you'll never hear the pump itself. But you may hear one or even two well pump relay switches that click when the pump is started or stopped. If your well pump is a small horsepower unit the pressure control switch on or close to your water pressure tank turns the pump on and off in response to water pressure - and the relay may emit a click at the start and stop of the run cycle.

If your pump is a higher horsepower unit your pressure control switch in turn operates a separate, heavy duty well pump relay switch usually mounted nearby, and that switch is what actually turns the pump on or off. (The smaller switch can't handle high amps switching without risking burning the contact points, so two relays are used).

If you hear the clicks very frequently, say every 20 seconds or less, your pump is turning on and off too frequently - search InspectApedia for "well pump short cycling" for diagnosis and cure advice if needed.

Jeannie:

Since A/C and well pumps are completely independent systems, I have to guess that perhaps they are (and should not be) on the same circuit which is overloaded and is tripping a breaker?

Question: dug well runs dry in summer - can I have a water truck deliver water into my well?

(Sept 5, 2012) Corey M said:
I have a dug well that is just over 30ft deep. Due to an unusually dry summer I have had my well run dry several times (four teenage daughters!) the pump recently burnt out and I had to replace it and the pressure switch (30-50).

I have been able to refill the well using 45gal drums with municipal water, but I would like to know if I can install one of the drums as an indoor emergency storage tank close to the pressure tank in the basement and some sort of "Y" gated valve to manually switch between the well and the indoor tank. That way I could still at least have water in the system to allow flushing toilets or running limited amounts of laundry or dishwashing while the well replenishes itself.

Reply: not a good idea

Corey, pouring water back into a dried out water well to "refill it" is probably not useful and provides no lasting relief, and will perhaps lose and thus waste some of the water poured therein.

To install an emergency water system you could indeed feed your local water pump from water drawn from the 45-g steel drum, though it's not going to last very long. I'd give some thought to a larger water storage tank installed in the building or outside above or on top of the building if the structure permits; when you have water in your well, even if it's at a very slow recovery rate, you can use it to slowly fill the larger storage tank that will act as a buffer to give functional water when you need it, recovering slowly when water is not being used.

Question: can't find the well, no water.

(Feb 13, 2014) Bill said:
Unable to locate our outside well and we have no water. No visible pipe above ground. Suggestions?

Reply:

If the well piping is metal a plumber can trace its location using an electronic tool. Follow the ppe to the well.

Look a around the water tank and equipment for a sketch left by a prior owner or service tech.

Call prior owners and ask I'df they are alive

Call local well drillers to ask if one of them has a record of drilling your well- I have had very good luck with this approach

Look around on the site for reasonable well locations e,g, awayy from septic

Depending on well age you may spot a long shallow depression marking the original well pipe excavation.

Finally, last resort, excavate outside making a cross trench near the well pipe exit from the building. Note pipe direction, move out 10 or 15 feet and repeat - this may be less total digging than just digging up the whole pipe to follow its length to the well.

At SEPTIC DRAINFIELD LOCATION

a series of videos show walking a home site to identify most-likely locations for private water well and septic system compnents.

Keep us posted.

Question: PVC water piping

(Dec 20, 2014) Anonymous said:
Can i use pvc as delivery pipes

Reply:

Yes

See PLASTIC PIPING ABS CPVC PB PEX PPR PVC

...

Continue reading at WATER PUMP, SUBMERSIBLE - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• ARTESIAN WELLS, WELL SPOOLS - topic home
• DIAGNOSTIC TABLE for WATER PUMPS
• SUBMERSIBLE PUMP TORQUE PROBLEMS & SOLUTIONS
• WATER PRESSURE PROBLEM DIAGNOSIS TABLE
• WELL FLOW RATE

Suggested citation for this web page

PUMP, SUBMERSIBLE OPERATION at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER SUPPLY, PUMPS TANKS WELLS

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