Well Pumps
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Troubleshooting Well Pumps

  • Troubleshooting any aspect of a plumbing system requires knowledge of the item(s).

  • Well pumps work directly with electricity and in many instances a repair diagnosis requires a plumber to test the electrical system.

  • Do not attempt any repair especially electrical repairs if you are not qualified.

  • Return to our Home Page for contact information

  • Review the Tricks of the Trade section for more helpful information.

  • To calculate the amount of water your well contains in gallons Click Here for a MS Word document.

  • Below are the basic formulas in case the document is available.
     

  • Cylindrical Capacity Determination

  • When using dimensions in inch form: Diameter x Diameter x 0.7854 x depth in inches divided by 231 = gallons

  • When using dimensions in feet form: Diameter x Diameter x 0.7854 x depth in feet divided by 7.5 = gallons

  • Example of inch method using a 6" diameter well that is 100 feet deep.

  • There are 231 cubic inches in one gallons of water. (if using feet version of the formula, there area 7.48 (7.5) gallons in one cubic foot)

  • 6" x 6" x 0.7854 = 28.27 (square area of a 6" circle) (feet formula = 0.5 x 0.5 x 0.7854 = 0.196)

  • 100 feet x 12" = 1200 (cubic inches in 100 feet) (feet formula = 100 feet x 1 = 100)

  • 28.27 x 1200 = 33,924 (cubic inches in a 6" round x 100 feet well) (feet formula= 0.196 x 100 = 19.6)

  • 33,924  ÷ 231 = 146.86 gallons of capacity. (feet formula = 19.6 x 7.5 = 147 gallons of capacity)

  • This also tells you that one foot of 6-inch diameter well casing holds 1.47 gallons of water

  • Now you must deduct the static level, which is the recovered level of the surface water below the ground elevation.

  • Deduct 1.47 gallons for every foot the static water level is below the ground elevation.

  • You also must deduct the height the submersible pump or foot valve is above the bottom of the well. If you do not know that distance, assume that it is a minimum of 10 feet.

  • If you were to assume that the static level was 10 feet below the ground and the pump was raised 10 feet above the bottom of the well, that would mean that out of the 100 feet well depth, only 80 of that is useable water.

  • You also would not want to have your system drawdown the entire storage capacity. This would cause erosion on the sides of a well that is not completely lined. This erosion causes sand, debris or rocks to cave into the well.

  • For 4" diameter wells, each foot of depth contains 0.65 gallons of water

  • For 8" diameter wells, each foot of depth contains 2.61 gallons of water

Gallon Capacity of Round Well per One Linear Foot
(Using formula D x D x 0.7854 x Height in inches ÷ 231)

Diameter US Gallons
4" 0.65
6" 1.27
8" 2.61
18" 13.22
 24" 23.5

          Well Pump Troubleshooting Guide

Approaching a well pump repair situation requires knowledge of electricity. Adequate electrical testing equipment is essential for correctly diagnosing voltage, amperage and continuity of components or systems. Motors that are malfunctioning due to excessive resistance draw more amperage than its normal operating cycle. Typical amperage reading on a malfunctioning motor will be three to six times higher than its normal operating amperage reading.

Problem

Possible Cause

Repair Procedure

Possible Solution

Motor will not start

Circuit breaker is tripped or faulty fuse

Check circuit breaker
Check fuse

Reset circuit breaker
Replace fuse

Motor will not start

Incorrect Voltage

Check Voltage

Call service provider

Motor will not start

Damaged wiring

Inspect all wire insulation and terminal connections

Replace wiring and / or
terminal connections

Motor will not start

Faulty motor

Check for high Amperage

Replace motor

Motor will not start

Poor alignment between motor and impeller

Check for high Amperage

Align motor with impeller

Motor will not start

Faulty pressure switch

Check for point corrosion

Clean points

Motor will not start

Faulty pressure switch

Check for voltage transfer between terminals

Replace if required

Motor will not start

Plugged pressure
switch nipple

Remove, inspect, clean or replace nipple

Release or reinstall nipple

Motor will not start

Faulty control box

Check for voltage transfer between terminals

Replace control box if required

Motor will not start

Obstruction in
impeller housing

Inspect for sand or debris
Check for high Amperage

Clear obstruction

Motor will not start

Overload is tripped

See trouble shooting chart for overload is tripped

See trouble shooting chart for overload is tripped

Motor starts often

Leak in piping system

Inspect visible piping first
Test buried or well piping

Repair leak

Motor starts often

Foot valve or check valve not closing properly

Inspect for obstruction,
worn seat or disc

Clean or replace

Motor starts often

Pressure switch setting is incorrect

Check pressures at the pump "On" and "Off" modes

Adjust to have 20 pounds between modes

Motor starts often

Faulty pressure switch

Check pressure modes and attempt adjustment (above)

Replace pressure switch

Motor starts often
Bladder type tank

Tank is water logged

Depress air inlet valve, inspect for water in tank

Replace tank if bladder is defective or recharge

Motor starts often
Bladder-less tank

Tank is water logged

Drain tank

Change aspirator device (air / volume control)

Overload is tripped

Control box is defective

Check voltage transfer between terminals

Replace box

Overload is tripped

Voltage is incorrect

Check voltage supply

Contact electrical supply provider

Overload is tripped

Control box has overheated

Notice the location of the control box

Install in a shaded or partial sunny area

Overload is tripped

Control box has overheated

Notice the location of the control box

Install in an area away from heated area

Overload is tripped

Motor is defective

Check amperage

Replace motor if required

Overload is tripped

Defective wiring

Inspect all wiring and terminal connections

Replace or repair wiring and connectors

Overload is tripped

Pump is wired incorrectly

Review wiring diagram

Wire per manufacturers wiring diagram

Overload is tripped

Motor is in an area not properly ventilated

Notice location and possible air obstructions

Provide adequate ventilation to motor

Motor always runs

No water flow due to sand or obstruction

Inspect check valve to verify if is opening

Clean piping of sand or obstruction or replace

Motor always runs

No or low water flow due to loose shaft connection

Check impeller
connection to shaft

Tighten impeller connection to shaft

Motor always runs

No water flow due to broken shaft

Inspect shaft

Replace motor

Motor always runs

Leak in piping system

Inspect visible piping and test all hidden piping

Repair leaks

Motor always runs

Malfunctioning
control box

Test voltage transfer between terminals

Replace box if required

Motor always runs

Pressure switch is defective

Inspect points to see if they are "welded" together

Replace pressure switch

Motor always runs
Submersible Pump

Intake screen is plugged

Pull pump and inspect screen

Clean and determine cause

Motor always runs
Aboveground Pump

Foot valve screen
is plugged

Pull drop pipe and inspect screen

Clean and determine cause

Motor always runs

Low well water level

Pull pump and / or piping

Check water level
and depth

Motor always runs

Low well water level

Pump is oversized for well capacity or yield

Test yield of well and size accordingly

Motor always runs

Well has collapsed

Attempt to free pump or piping from collapsed soil

Raise pump or piping if well is deep enough

Motor always runs

Well has collapsed

Attempt to free pump or piping from collapsed soil

Have well cleaned and lined or new well

Circuit trips or fuse blows on start up

Obstructed impeller from sand or debris

Inspect impeller for obstruction

Clean impeller and determine the cause

Circuit trips or fuse blows on start up

Defective wiring

Inspect wiring

Repair or replace wiring

Circuit trips or fuse blows on start up

Wiring is grounded to casing

Perform Ohm test on well casing and wiring

Repair or replace wiring in well

Circuit trips or fuse blows on start up

Motor winding is defective

Perform Ohm test on winding

Replace motor

Circuit trips or fuse blows on start up

Defective capacitor
(three wire type pump)

Locate in control box,
perform Ohm test

Replace if defective

Circuit trips or fuse blows on start up

Defective relay coil
(three wire type pump)

Locate in control box, perform Ohm test

Replace if required

Circuit trips or fuse blows on start up

Control box is overheated

Notice location of control box

Locate in shaded or away from heat

Circuit trips or fuse blows on start up

Voltage supply is incorrect

Perform voltage test

Call electrical service provider

Add Your Own Troubleshooting Information
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Problem

Possible Cause

Repair Procedure

Possible Solution