Relationship between the water pressure tank and building water pressure or flow rate:

How to track down the reason for bad water pressure in a building.

This article describes how the water pressure tank or "well tank" affects water pressure and flow in a building - part of diagnosing bad or lost water pressure.

How might a bad water pressure tank be related to water pressure or water supply loss symptoms

The basics process of diagnosis and the costs of the repair are explained. Consumer advice on saving money on well repair costs includes a review of the parts and labor costs of a typical well pump and pressure tank replacement case. Page to sketch is courtesy of Carson Dunlop Associates, a Toronto home inspection, education & report writing tool company [ carsondunlop.com ].

1. A bad or defective water pressure tank or water tank bladder  can cause well pump short cycling which in turn is hard on the pump (damages the pump) and, especially with an older pump, might push it over the edge of failure.
   
   When the water pump fails the building will lose water supply completely (unless it is served by an artesian well). Our photo (left) shows a Well-X-Trol internal-bladder well tank installed below a one-line jet pump.
   
   See WATER TANK BLADDERS & CAPTIVE AIR for details on how captive air or bladder type well tanks work.
   
   See WATER TANK BLADDER PRESSURE ADJUSTMENT if you need to adjust or fine tune the air charge in a bladder type water tank.
2. A leaky or defective steel or glass-lined well tank (tanks without an internal bladder) often loses its air charge and leads to short on-cycles of the water pump. Water tank problems can also lead to poor water pressure or flow in a building.
   
   To review loss of air charge, water pump short cycling, water pump pressure control settings, and other water tank repairs
3. see WATER TANK AIR, HOW TO ADD and
4. also WATER PUMP & WATER TANK REPAIRS.
   
   Other detailed articles on this type of water tank are found at

• WATER TANK AIR VOLUME CONTROLS
• WATER TANK AIR ADD AT AIR VALVE
• WATER TANK AIR ADD BY DRAINING
• WATER TANK AIR HOW MUCH TO ADD
• WATER TANK AIR HOW OFTEN TO ADD
  
  At WATER TANK LIFE EXPECTANCY we discuss about how long you can expect various types of well tanks or water tanks to last.
  
  At WATER TANK PRESSURE CALCULATIONS we get very detailed about how the peformance of a water tank might be affected by extremes in temperature to which the tank is exposed.
  
  Putting your well tank in hot sun in Arizona or Mexico will give different performance than you can expect from the same tank in a building interior and different again from a tank exposed to sub-zero weather in parts of Canada or northern states of the U.S. Adjustments to the well tank's air charge or operating pressure may be needed.
  
  Installing a water pressure tank where it is exposed to freezing can damage the tank or its controls and is likely to lead to need for pressure tank replacement.

A water pump might be at end of its life and about to burn up but still work after a cool-down cycle (some pumps have a thermal overload that shuts them off and an automatic reset - especially one that is inaccessible such as a submersible).

In this case water pressure and supply will return after the cool-down problem but the failure is likely to be recurrent. This is not a problem with the well tank.

Diagnostic Steps to Figure Out if the Problem is the Well Tank or Something Else

Here is a list of well and water pressure diagnostic steps that might help decide if the problem is with the well tank or something else:

• Bad or No water pressure? See WATER PRESSURE LOSS DIAGNOSIS & REPAIR for a step by step detailed guide to diagnosing and correcting bad water pressure or total loss of water pressure. Before changing a water pump or control, we need to know why the water pressure or water flow is poor.
  
  Also see our separate WATER PRESSURE PROBLEM DIAGNOSIS TABLE in summary table form.
• Intermittent water pump cycling is discussed at Intermittent Water Pump Cycling When No Water is Running - this means that the water pump comes on for no apparent reason.
• Short cycling of a water pump means that the water pump turns on and off too rapidly or too frequently when water is being run in the building.
  
  See What Causes 'Water Pump Short Cycling'
  
  and Water Tank Repairs: Diagnose 'Water Pump Short Cycling'.
• Loss of water pressure means that the pressure with which water enters a plumbing fixture has become too slow, or is sometimes too slow or weak in water flow rate, or water flow may stop entirely.
  
  See Water Pump Problems? How to Diagnose & Repair Poor or No Water Pressure.
• Details on how to repair the water pump pressure control switch are discussed
  
  at How to Repair the Water Pump Pressure Control Switch The illustration at page top is courtesy of Carson Dunlop, Inc. in Toronto.
• How to boost water pressure in a building by installing a pressure booster pump and pressure tank is discussed in detail
  
  at WATER PRESSURE BOOSTER PUMP
• 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 Poor or Lost Water Pressure and Flow: we still have water flowing but pressure and flow quantity are reduced.
  
  See WATER PRESSURE LOSS DIAGNOSIS & REPAIR
• 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.
  
  Also see WATER TANK AIR, HOW TO ADD
  followed
  
  by WATER TANK BLADDERS & CAPTIVE AIR
  
  and WATER TANK BLADDER PRESSURE ADJUSTMENT
• 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 PRESURE SWITCH REPAIR
• How to boost water pressure in a building by installing a pressure booster pump and pressure tank is discussed in detail
  
  at WATER PRESSURE BOOSTER PUMP

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2020-07-28 - by (mod) -

Re posting


AUTHOR:Michael James (no email)

COMMENT:Given a 500 gal tank full of water at sea level. What is the PSI at the very bottom of the tank??? mjames@unitysystems.net



Moderator reply

You need to state the tank depth, else there is no correct answer

On 2015-09-02 - by (mod) -

Carl there may be two problems (though Occam's razor says we ought to take the simplest explanation first)

1. the water tank is waterlogged - that causes short cycling

2. the pressure switch may be debris clogged

3. double check that there are no water leaks; there could also be a bad check valve or foot valve - if you see pressure dropping and water into the building is shut off I suspect the latter.

On 2015-09-02 by Carl

I have a well on our farm house with a 44 gal. WelTrol tank. Yesterday it started short cycling when no water was being used

. The tank feels like it is completely full of water. I can't shake it and tapping it anywhere, even at the very top, sounds solid, no metal ring like a healthy tank sounds. It cycles on and off every five (5) seconds. It runs up to about 80 cuts off then back on again at 50 and all that takes 5 seconds or so. I'm guessing the bladder has completely failed.

The tank was installed in 1992. So that makes it 23 years old. A new pump was installed about ten years ago and the tank was fine then. I'm out in the country and it will take a day or two to get a new tank.

If I add air to the tank will that let me limp by for a day or two?

Or should I let some irrigation sprinklers run (they're plumbed right off the main supply coming from the pump, and that would keep the pump running during the day until we can replace the tank. I thought I had noticed in the last week or so that the pump was coming on a little too often but I assumed someone was using water and didn't take the time to check it out. Any help would be appreciated.

Thank you. Carl in South Carolina
I was having a problem using my phone to navigate this forum. Could I please ask you to email me your response at cmubarak@earthlink.net
Thank you very much.

Question:

(June 15, 2014) Tim said:
I have a new 20 gal. water tank set with 26psi in the tank. I have a new 30-50 pressure switch. All connections appear to be correct. When I start the presure switch and hold it for awhile, the tank does not fill. The pump appears to be in working order because we can fill a bucket quite readily by using the drain and holding the switch on start. When we close the drain valve, there is no evidence of the tank filling.

(Sept 9, 2014) Brenda said:
We have the same problem and the bladder does hold air. The pump is pumping water to the tank, and it comes out with a hose but hardly any is going into the tank itself.

Reply:

Tim,

Sometimes an internal bladder type water pressure tank won't accept water because the bladder has collapsed and is stuck to itself.

See WATER TANK BLADDER REPLACEMENT

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Continue reading at WATER TANK DIAGNOSIS & REPAIR or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• WATER PRESSURE PROBLEM DIAGNOSIS TABLE
• WATER TANK AIR PRESSURE ADJUSTMENT
• WATER TANK PRESSURE CALCULATIONS
• WATER TANK REPAIR PROCEDURES

Suggested citation for this web page

WATER TANK RELATION to WATER PRESSURE 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 & SPRINGS

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