One Line Jet Pump (C) Daniel Friedman Diagnostic Guide for Poor Water Pressure or Lost Water Pressure - Table 1 of 3
Troubleshoot water pumps, pressure switches, & other causes of water pressure & flow trouble

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This WATER PRESSURE PROBLEM DIAGNOSIS TABLE series provides a table giving step by step checklist for diagnosing water pressure, water pump, and water well problems. We give diagnostic and repair procedures for both municipal water supply problems and well water supply problems.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Table of Diagnostic Steps for Poor Water Pressure from a Pump & Well System

Checklist of water pressure problem diagnosis and repair steps. Well pump problem diagnostic checklist. Well water problem diagnostic checklist. Water pressure loss or poor water problem diagnostic checklist. How to diagnose loss of water pressure or loss of water in a building - both municipal water supply and private well systems are addressed.

Article Series Contents

Keep in mind that if water is running elsewhere in the building (another shower, sink, dishwasher, clothes washer, garden hose, etc) then the water pressure you will observe at your location will usually be reduced.

Table 1: Pump Won't Run, Wont' Stop Running, or Cycles Rapidly

Well Pump Will Not Start 


Pump Will Not Run


Check that electrical power is turned on and being delivered to the pump control switch and to the pump.

  1. Check for a tripped circuit breaker or blown fuse
  2. Check for low voltage
  3. Check for broken or disconnected electrical wires
  4. Check for a defective motor
  5. Check for a jammed or broken impeller assembly
  6. Check that the pressure switch is closed and sending power to the pump

If a check (with power off) shows that you cannot turn the pump impeller assembly the impeller or pump motor itself is bound and needs repair or replacement.

Other pump motors may fail to start if the motor has tripped a thermal overload switch (some may re-set automagically), or if the motor has a failed start/run capacitor.

If turning on the motor trips the circuit breaker or blows the fuse there is a wiring short circuit or a short circuit in the pump motor or bontrols.

Symptoms such as a humming motor means the pump has power but is not able to operate.

Watch out: turn off the pump in these cases to avoid further damage, shock or fire.

WATER PUMP ELECTRICAL SWITCHES - electrical power switches


ELECTRIC MOTOR DIAGNOSTIC GUIDE - how to test an electric motor

Check the water pressure at the tank & by using an independent pressure gauge (in case the tank gauge is stuck)

  1. Water pressure is below pressure switch cut-in pressure:

    1. If the Pressure Switch includes a low-pressure cut-out pump protection feature Hold the lever in the "Run" or "On" position. Pump should start.
      1. Keep holding the lever "on" until pressure is above the cut-in.
      2. Release the lever.
      3. If pump cuts out again then the water supply from the well is low. Do not keep running the pump or it may be damaged. Wait until the well has recovered and try again. (Hours or more).

    2. If the Pressure Switch does not have a pump protection feature:
      1. Leave the pump turned OFF to protect it from damage.
      2. Check the water level in the well - if low wait for the well to recover before turning the pump back on.

WATER PUMP PRESSURE CONTROL REPAIR - pump relay turns on pump or turns on a separate water pump relay

WATER PUMP RELAY SWITCH - heavy duty relay turns on submersible pump

WATER PUMP ELECTRICAL SWITCHES - electrical power switches

WATER PUMP DIAGNOSTIC FAQs - helps sort out problems with well pumps & booster pumps

The Form M4 (low pressure cut-out feature) is only available on the Square-D 9013FSG & 9013FYG pressure switches.

Schneider Electric offers this additional detail about the low pressure cutoff feature included in these two pressure control switch models:

The low pressure cutoff remains fixed at 10 psi below the low pressure cut-in for the pressure switch. Although it is not independently adjustable, it will follow the low pressure set point. However, the pressure switch will not be effective if the cut-in point is set below 10 psi. - Op. Cit.


Pressure switch does not turn on in response to drop in water pressure:
  1. Check for debris-clogged sensor port on the pressure switch diaphragm or mounting tube. Clean or replace these parts.
  2. Check for burned pressure switch contacts.
  3. Check for debris-blocked pressure switch contacts: mud dauber wasps, insects, crud in the switch can prevent its operation
  4. Check for incorrectly-adjusted pressure control switch Differential or Range Nut Adjustments
  5. Check for damaged pressure sensing diaphragm on the pressure control switch.
  6. If you have been fooling with the pressure control switch settings they may be adjusted out of range.

PRESSURE SWITCH NUT ADJUSTMENTS - how to set the Differential & Range nuts to adjust the pressure control switch cut-in and cut-out pressures.

If the pressure switch contacts are burned possible causes include:

  1. Pump has been short cycling, burning and arcing the contacts
  2. Pump draws excessive current due to motor size or due to incipient motor failure. If this is the case replace the switch with a heavier duty one or fix failing motor or if necessary install a separate heavy duty pump control relay with a higher rating.

Burned pressure switch contacts can be replaced in many pressure control switches.

A replacement parts kit typically includes a new set of contacts and a new pressure sensing diaphragm actuator.

Well Pump Keeps Running, Pump Will Not Shut Off 

Common causes include:

  1. Water is running or at the building
  2. A water pipe or well piping is leaking
  3. The pump is damaged and cannot reach cut-off pressure
  4. The pressure control switch cut-off is set too high
  5. Water level in the well is too low and a tailpiece is recycling water through the pump system
  6. Pump has lost prime due to leak in well piping or a failed check valve or foot valve
  7. If you have been fooling with the pressure control switch settings they may be adjusted out of range.

Less common causes:

  1. Clogged pressure switch sensor port, not sensing increase in water pressure.
  2. Worn pump impeller
  3. Broken blade on pump impeller
  4. Debris clogging at pump inlet or impeller
  5. Debris clogging at pump outlet
  6. Partly-closed valve or clogged water filter at pump outlet
  7. Other worn pump internal parts
  8. Damaged pressure sensing diaphragm on the pressure control switch

Watch out: turn off the pump to avoid damage.


Watch out: a pump that does not turn off, it is actually delivering water, creates a dangerous over-pressure condition in the system. See more warnings just below.

Well Pump Turns On and Off to Often - water pump short cycling 


Pump turns on every time water is run

Most common cause

  1. Water-logged pressure tank
  2. Improper air pre-charge in an internal-bladder type pressure tank (too little)
  3. Very rapid cycling can be due to a clogged water filter or any blockage at the outlet side of the pump.

Less common causes

  1. Under-sized pressure tank
  2. Pressure tank diaphragm damaged or stuck to self
  3. Leak in water supply piping (big leak)
  4. Debris-clogged pressure sensor port on the pressure switch or its mounting / sensor tubing


Watch out: a clogged sensor port or tubing at the pressure switch can delay the response of the switch to rising water system pressure and can cause the pump to run after it should have turned off. A safety hazard.

Well Pump Runs Intermittently for No Apparent Reason - no water running

Most common cause:

  1. Slow water leak such as a running toile
  2. Leaky check valve or foot valve in the well piping system causing loss of prime in pump & well piping
  3. Debris-clogged pressure sensor port on the pressure switch or its mounting / sensor tubing can cause delayed sensing of a drop or rise in water pressure.


Watch out: a clogged sensor port or tubing at the pressure switch can delay the response of the switch to rising water system pressure and can cause the pump to run after it should have turned off. The resulting high water pressure in the system risks leaks or even a dangerous burst pressure tank or piping - not just a leak but a source of injury.

This sporadic or unexplained "on-cycles" of a pump is a different problem from a well or system that sometimes simply runs out of water. For that problem

Pump Runs, shuts off immediately after start then runs again: Pump Chatter

Most common cause:

  1. Pump capacity too high for water outlet
  2. Clogged water filter or closed or mostly-closed valve at pump outlet

May occur when a new pump is installed especially if it's a higher horsepower than its predecessor.

Install a water pressure surge protector at the pump outlet. Schneider / Square-D offer these parts in quantity (PN 1530S6G1) but buy just one from your plumbing supplier.


These diagnostic suggestions include, expand, and adapte information from : "Preventive Maintenance and Troubleshooting Guidelines for Class 9013F and 9013G Pressure Switches" (2007), Original source: Schneider Electric USA 8001 Knightdale Boulevard Knightdale, NC 27545 USA 1-888-SquareD (1-888-778-2733)

To select the proper Square-D pressure control switch see to the Schneider Electric catalog Commercial Pressure Switches Types F and G Class 9013
(9013CT9701), Industrial Pressure Switches (9012CT9701), or Nautilus™ Electronic Pressure Sensors, XMLE, XMLF, XMLG (9014CT0201).

National Pump Company, "Betta Flo Jet Pump Installation Manual", National Pump Company, LLC., 7706 North 71st Ave. Glendale, AZ 85303 Tel: (800) 966-5240, offices in the U.S. in Arizona, California, Florida, Georgia, Mississippi, Texas; Email:, retrieved 1 April 2015, original source:

Tractor Supply Co., "CountryLine Cast Iron Jet Pumps Owners' Manual", Tractor Supply Co., 293 Wright Street, Delavan, WI 53115 Phone: 1-800-535-4950 Fax: 1-800-526-3757 Web Site:, retrieved 1 April 2015, original source:

Notes: Some of the well pump troubleshooting suggestions in this list can be found at the Betta-Flo Jet Pump Installation Manualfrom the National Pump Co.


Continue reading at TABLE 2: PUMP RUNS, WEAK or NO WATER PRESSURE or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see WATER PRESSURE PROBLEM DIAGNOSIS TABLE FAQs Q&A posted originally at this article

Or see this

Water Pressure & Water Pump Article Series Contents


Or see WATER FLOW RATE CALCULATE or MEASURE - how much water comes out of faucets & fixtures

Or see WELL FLOW RATE - how much water is in the well


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