Poor water pressure diagnosis FAQs (C) Daniel FriedmanLow Water Pressure Diagnostic FAQs
Problems with weak water pressure

  • POST a QUESTION or READ FAQs about diagnosing problems with the well water pressure tank or water storage tank that show up as pump operating problems

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Low water pressure diagnostic FAQs: this article provides answers to frequently-asked questions about how to diagnose problems with slow, weak, or poor building water pressure & flow.

These bad water pressure questions & answers help sort out the causes of water pressure problems and help determine if the problem appears to be at the water pump, water pressure tank, water piping, or water source such as a private well or water storage tank.

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.

Low water pressure problems, questions & answers

Causes of bad water pressureQuestion: My water pressure is really low but we don't know where to start in figuring out what's wrong

My water pressure is low and I barely get any flow when I try to fill the tub. The hot water is still hot through out the house but when you flush the toilet the water almost stops if your using the sink or the shower. Any ideas on what the problem might be or where I can start. - Rachel

Reply: check these water pressure diagnosis articles first

Rachel, we have two articles that give step by step diagnosis of water pressure problems. Please see WATER PRESSURE LOSS DIAGNOSIS & REPAIR

or for a water pressure troubleshooting guide in table form see our WATER PRESSURE PROBLEM DIAGNOSIS TABLE

And don't hesitate to ask if that material leaves you with more specific questions - I'll do my best to help further.

More reader questions and answers about low water pressure diagnosis and repair

On 2017-01-14 by (mod) - no water at some locations but good water pressure at others


I suspect that someone left a shut-off valve closed near your pressure tank

On 2017-01-14 by Marca Hinkley

had pipes on well fix that goes to house now no water to house but one faucet on outside is got water

On 2016-12-10 by (mod) - muddy water with black grit comes out of well


I would ask a local well installer/repair company to check the well and well casing for damage to the casing, low water level in the well, or the foot valve too close to the well bottom.

On 2016-12-10 by Bill

Hello, I have a well that we replaced the pump about 10-12 years ago, my problem was happening about once a year or so, you would turn on the water and all of a sudden it would become very very muddy looking, and there would also be black grit almost like charcoal, it would become so bad that you couldn't flush the toilet because it would clog up the valve in the toilet and i'd have to replace it.

Now this problem is happening like every couple months ? Once I let everything settle down for hours I return and use the cold water it runs off and becomes clear again, and we go on for months without a problem, do I have to have my well dug deeper to find a better water source or deeper, or do you believe I should think about the pump being replaced again?

when we did replace the pump the last time I checked it and it would not operate at all when we pulled it and hooked it up outside the well, but why am I getting all this muddy/rust/grit looking love from my pump could the pump be pumping this because of a lack of water or do things move in a drilled well and water discoloration can happen because of it?? Any help would be greatly appreciated, Thanks!!

On 2016-11-19 by (mod) - bubbles come out with the water

Sounds as if there is marginal flow rate into the well and perhaps a piping leak

See the diagnostic steps at AIR DISCHARGE at FAUCETS, FIXTURES

On 2016-11-19 0 by Brent

My pump has decent pressure for a bit then loses all pressure but water still comes out, then bubbles come out with the water (filling tub with a hose). I shut the water of at the tap and it pressurizes again . I believe the well is refilling to slow for the pump . Well was drilled in the 90's

On 2016-11-08 by (mod) - not enough water pressure to use the shower


In the article links at the end of the article just above on this page see MUNICIPAL WATER PRESSURE DIAGNOSIS - If your water supply is from a city or municipal water system
- for help diagnosing and fixing the trouble you cite.

On 2016-11-06 by Robin Shultz

Hello I have a modular home ... and in the Master bathroom which is the closet to the water supply ... I have not enough water pressure to fill the garden tub fast enough or to use the shower head

... when I moved in I didn't check it to see if everything was ok ... so after purchasing a new really nice shower head

... I ended up having to change the spout because the knob on the spout wasn't working. So after changing the spout ... I now have very little pressure to fill the tub and definitely not enough to use the shower head. HELP!!!

On 2016-06-28 by (mod) - how to calculate the lower setting of pressure switch for a private water system ?

Sorry I don't understand your data nor that it's normally used to answer your question.

Typically residential pressure control switches are factory-set at a CUT-IN / CUT-OUT of 20/40 or 30/50 psi. The pressure tank is set to 2 psi blow the cut-in.

On 2016-06-28 by anis

how to calculate the lower setting of pressure switch for a private water system ?
Suction head = 18feet
Discharge head = 20
Point of use pressure =21 psi

On 2016-02-09 by (mod) - checked the pressure and found it was down to 21psi


Upping the pressure in the water pressure tank will give you a longer draw-down cycle before the pump turns on but it won't increase the overall system water pressure. That's a function of the pump's capacity in gpm as well as the length, bends, constrictions in the piping, and if the well yield is limited, possibly also any pump protection devices installed.

But when water flow slows to a trickle before the pump turns on I suspect that the pressure control switch is debris clogged and needs replacement.

On 2016-02-09 4 by Israel

My water pressure was slowly decreasing, especially if being used by a couple sources, so I drained my pressure tank, checked the pressure and found it was down to 21psi. I slowly repressurized it using a bike pump back up to 28psi.

Now, the pressure is great again but will slowly start decreasing all the way down to a trickle before the pump kicks in and it's back to great pressure again. Am I looking at a higher setting than I realized, or what is causing this?

On 2016-01-31 by (mod) -


I suspect a well piping leak or a poor well flow rate.

On 2016-01-31 by Terri

We had very low water pressure. assumed it was a faulty pump (submersed). Replaced pump, piping,tank but still pressure that should come up to 50 will only go up to 38. Then when water is turned on it plummets down to 20. What are we missing that could be the problem?

On 2015-09-29 by Ed

Hello we recently moved to a rural home and it's been quite a learning curve. One very annoying issue at the moment is our water pressure. I cannot tell what pump is used since it appears to be underground. I initially changed out the pressure switch as it was set at 20/40 and looked a bit worse for wear.

I changed to a 30/50 and followed the guides on setting the pressure. While the tanks cut-in and cut-off work as set, the outlets beyond this tank all have very poor pressure. Even our washing machine now keeps erring out due to slow water intake.

If we try and run a sink faucet and bath faucet at same time the sink goes down to a trickle. The discharge outlet at the tank however seems to really push the water out well when I open it and if I did the calculations correct I got about 7gpm at it. As I do not know much about these things the piping from the pressure tank to the water softener seems wrong to me.

It is a thick black pipe which exits the pressure tank T for about 2 feet to the wall then elbows and runs up the wall about 6 feet, elbows again and runs across the wall for about 10 feet and yet another elbow and runs about 12 feet along the wall before going down to the water softener. My questions would be is this not unnecessary and causing pressure loss?

Can I just move the water softener right next to the pressure tank since there is more than enough room and get rid of that 25ft+ piping? Thank you very much for any advice

On 2015-06-28 by tony

40ft deep well, pump running 24/7, 30/50 press switch, press tank at 30psi, flow at kitchen faucet less than 1gal/min, pump is 7yrs old, water is clean, what is best guess at prob?

On 2015-03-21 by (mod) - slow pump discharge, gray sediment


By slow discharge rate I infer you mean that that the water delivery rate is slow I'd look first for a leaky connection at the area of repair.

And the 95 psi tank pressure escapes me. I cannot understand what you are doing - that pressure is very high possibly very dangerous if it exceeds the tank's rated pressure.

On 2015-03-21 by Kevin Hromas

I had a small leak in the PVC pipes between the well-head and the pressure tank so I shut off the well and replaced the leaking pipes, re-pressurized the tank to 95 PSI and now have a very slow discharge rate.

I have a problem with grey sediment in the water due to the vein of coal down there but have a filter system up top. Could that sediment have settled back into the pump and is the cause of my problems now?

On 2014-12-24 by (mod) - pump slows to a trickle

Jim if you set the pressure switch to higher than the pump can reach it will run until it burns-up.

In the More Reading links above try the simple diagnostics at


On 2014-12-24 by Jim

Our water pressure was low, so then I changed settings on the switch. The water pressure got better but the pump kept running. I then did some more changing of the switch and now there is no water pressure in our bathtub and the pump continues to run. I have no idea what is wrong or what to do.

On 2014-08-30 by (mod) - water pressure starts off very good but in a few minutes it slows to a trickle


I'm not sure from the limited info in your note that the problem is the pump and switch = could your system have clogged pipes?

On 2014-08-30 by dennis

i have a deep well pump. my water pressure starts off very good but in a few minutes it slows to a trickle.

i have replaced the pressure switch.and still same problem my pump seems to be running i have current at controller.the pressure seems to be at 30psi. help

On 2014-08-21 by (mod) - If the pump is unable to deliver more than 10 psi


If the pump is unable to deliver more than 10 psi I'd be looking for

- low voltage
- a damaged or clogged foot valve
- a damaged or clogged pump impeller assembly
- a leak in well piping

On 2014-08-21 by Teresa Emerson

QUESTION- My private well pump has low water pressure. It is enough to keep the toilet filling when needed and to run the hose that comes off the well but says only 10 lbs of pressure.

We have replaced the well piping because it was the metal pipe and appeared to be close to the end of its life with lots of rust and actually broke when we went to lay it on the ground.

We also replaced the pressure gauge, the control switch and checked the wiring. It is a submersed pump and when we pulled and measured it was 198 feet deep with water approximately 100 foot down from ground.

With the pressure even directly off the tank not being very much and the house being slightly uphill from the pump and no evidence of any leaks from well to home (with the low 10 lbs and it only filling my toilet and water heater and pressure appears the same as at the well for both water heater and toilet and hose at well) I am lost on what to repair or replace next.

Question: huge water flow rate design question

My pump flow is 2500 cu meter per hour. The surge system consist of one large tank may be surge tank, one small tank, may be air vessel and 3 compressor (electric driven). Can you tell what are the system. Also can you tell me what are possible maintenance?? - Anand 11/22/11


Anand, you are describing a commercial grade water supply system with a huge flow rate, but with virtually no information about what's installed - so I'm reluctant to speculate about the system and its particular maintenance needs. You should ask a local plumber who is familiar with commercial water systems to take a look at your system, explain its components and functions, and give you maintenance recommendations.


I have a well 285 feet deep and I just started to lose water pressure, It will come back after about 2 hours. but I had to add air to the pressure tank. This lasted for about 48 hours and the same problem I am going to add air again and see how long it will last. any Idea of what I'm looking at replacing or is my well going dry. - Craig 2012 3/4/12


Craig, your description sounds as if your water usage rate exceeds the well recovery rate. The fact that water pressure returns suggests that the well is recovering during that two hour rest period. Especially if this problem is seasonal and shows up during the dry season, I suspect it's the well. You may want to add local water storage or ask your well driller about attempting to improve the well yield.

If you are not losing water pressure and flow totally, it may be that your well and pump include a protection device such as a tailpiece that slows the delivery of water to the home to keep it from exceeding the inflow rate of the well.

If it were a water pressure control switch or water tank problem, I don't think it would be seasonal and I don't think it would recover after two hours of rest.

Question: what could be causing my home to be losing water pressure over time

im having low pressure in my home i have everything underground because im in a double wide mobile home with just a crawl space i have been losing water pressure more and more over time

im glad i read this article i went outside and turned on my water from a hydrant attached next to well casing and had strong pressure did not measure pressure no gauge then turned on water in house and lost pressure outside and also not strong pressure inside

please need help to fix my set up was installed new in 1993 thank you - armco 9/13/11


If water pressure (not flow rate) is deteriorating over time the problem could be with the pump itself (wear and tear), with a a well that is deteriorating in its flow rate (the ability of the well to deliver water), a leak developing and increasing in the well piping, or even a waterlogged pressure tank. I suggest

or for minimum reading and a more concise list of water pressure problems and probable solutions in the form of a table, see

Question: poor water pressure for our lawn sprinkler systems, no water pressure tank installed

I don't have a tank so the water comes out by the pump so the pump runs the entire time I use my sprinklers. The pump runs but doesn't seem to run as high as it usually sounds so my water doesn't keep coming out. Do I need a new pump? I replaced it 4 years ago. - Debbie 4/15/12


Debbie, usually when we see a water pump system with no pressure tank installed, it's a special-purpose single-use system such as the lawn sprinkler system you are describing. In that case the presumption is that when the sprinklers are running the potential water flow rate through the system is greater than the gallons-per-minute capacity that the pump can deliver.

In that case, once we turn on the lawn sprinklers by opening a water control valve and then turn on the well pump, the pump will never "get ahead" of the water pressure or flow rate through the system, and it will just keep running indefinitely until you shut the whole system down.

If nothing has changed in your system, valves, controls, equipment, the problem could be any of several things including

Frankly this design makes me nervous because I worry that if the system and its controls were not set up by an expert we could turn on a pump without providing a pressure control switch for it - risking an overpressure in the water piping and bursting a pipe or possibly injuring someone.

Question: water pressure slows to a trickle

I have an in well pump, and what I'm getting is a big drop off of pressure in the house. It recovers after a while but does not last long ( bout a minute)then its just a trickle. I get good consistent pressure on the filter clean out valve but not in the house.

When water is running in the house, the pump cuts on & off while water is running but never the pressure it should.. Any ideas would be appreciated - Rob 9/4/12


Rob it sounds as if your water filter may be clogged. Also check for a waterlogged pressure tank - lost air charge.

Question: no water at house, good water at barn - varies

(May 25, 2014) Anonymous said:

I have a deep well that services my horse barn and my home. The barn has great pressure but the house is at about 20#. It makes no sense. When there is water being drawn at the barn we have no water at all. I have checked all couplings for leaks and found nothing.
Sometimes the pressure at the house is up near 30 .if there was a leak it would not be variable I think. Any ideas?



Look for a leak in well piping, or an obstruction, or a limited-flow-rate well that is protected in the well by a tailpiece.

Question: parts & manual for a Canadian Tire 1/2 hp Jet Pump 62-3525-6

Ted Brydges said:

Where do I find the jet in a mastercraft jet pump? The Canadian Tire product number is 62-3525-6 for the pump.Pump does not build up enough pressure.


Ted, on single line jet pumps such as the Canadian Tire 62-3525-6 the venturi or jet will be inside the housing on the front of the pump to which the well line attaches.

You will want to obtain a manual that includes a parts explosion diagram for your pump, and you may need to replace parts as well. I would not assume that the defect is the jet, though indeed we've had reports of occasional stones or debris entering a jet and reducing its flow capacity.

Other things to check when the pump is not building up enough pressure are a damaged impeller (inside the same housing) or a failing motor. If the motor is failing you may see an abnormally high current draw when the pump is running. Normal current draw on these 1/2 horsepower pump electric motors is around 10 1/2 to 11 Amps at 120VAC.

There are no motor lubrication ports on this pump, but if a bearing is failing the result may show up as high current draw, difficulty rotating the motor, or even leaks.

For parts for your Mastercraft pump (62-4003), call Canadian Tire customer service 1-800-942-3343

Canadian Tire describes this product as

Mastercraft Mastercraft 1/2 HP Jet Pump

Pump from a lake or well to a cottage, home, farm or campPump up to 25' deep ('shallow well')Ball bearing 115v motor features thermal overload protectionBuilt in ejectorHeavy cast iron constructionAutomatic 1/2 hp motor pumps 630-250 gph per 5 to 25 feetTank not included32.2lbs (14.6kg)


Continue reading at WATER PRESSURE PROBLEM DIAGNOSIS TABLE or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see this

Water Pressure & Water Pump Article Series Contents

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