6 Reasons Why Water Pressure Drops (2024)

Reviewed by: James Layton
Updated on:
January 16, 2024

Key Takeaways

  • To solve the issue, try flushing your pipes, replacing damaged parts, and checking the function of your well water pressure tank and other well elements if you’re on well water.

  • In some cases, you may need to enlist the help of a booster pump or professional plumber.

Keep reading to learn how to diagnose and fix fluctuating water pressure, whether you’re on municipal water or well water.

6 Possible Reasons Behind Fluctuating Water Pressure

Sometimes, a sudden and dramatic increase in water use, especially in a well system, can affect the pressure throughout the house. If you have guests, or a busy day of laundry, gardening, washing cars, and cleaning, cut down on your water use and see if it improves. 

Here are six likely causes of fluctuating water pressure in a city water or well water plumbing system:

City water supply changes

From a water main break to flushing the city’s hydrants, some activities of the city or the treatment plant could affect water pressure in nearby homes.

If you experience very low water pressure and you’re on city water, give them a call before you start tearing your house apart. It may improve within a few hours or days.

If your problem with low pressure is consistent and ongoing, consider adding a booster pump.

See our list of the best water pressure booster pumps to get going on better water pressure.

Specific fixtures 

Sometimes, homeowners will notice low pressure in the shower, the toilet, or a specific faucet, rather than the whole house. If that’s the case, it may be an easy fix.

In the shower or at the sink, inspect the fixture for clogs. Check the showerhead for clogs and either clean it or buy a new one.

Make sure the sink’s aerator isn’t clogged with buildup. If it is, give it a good soak and scrub.

For toilets, check the valve behind the unit and make sure it’s all the way open. There’s also a valve in the tank; you’ll need to check that too. If those are fine, you might just need a new supply hose.

Speaking of toilets, if your toilet is running all the time, constantly sounding as if you’ve just flushed it even when you haven’t, that could affect the water pressure in your house.

A running toilet is usually caused by a malfunctioning flapper valve, and you can easily fix it with one trip to the home improvement store.  

You don’t want to let this problem go on for too long because it increases the risk of flooding.

Air or clogs in the pipes

Air bubbles in the water supply can disrupt the flow temporarily. Air enters supply lines mostly through defective and cracked pipes, or, more likely, from the new installation of something attached to your plumbing, such as a water heater.

Air pockets develop a barrier in the pipes that stops and hinders the smooth flow of water even though the pressure level is fine. If that’s the case, you may notice a gurgling sound whenever you open the tap. 

Pipes can also get clogged due to sediment and rust or scale buildup, obstructing water flow, usually most noticeable at a specific point of use, but depending on where the clog or air bubble is, could be throughout the home.

If you think the problem may be scale buildup from hard water, it may be time for you to install a water softener.

See our list of the best water softeners to learn more about what kind to get.

If it’s a bad case of sediment or rust buildup, you may need a plumber to replace the clogged section of pipe.

And if it’s an air bubble, odds are it will go away a few minutes after you’ve opened up your faucets.

Faulty water pressure regulator 

Water pressure regulators, also called water pressure reducing valves, are required on homes on municipal water with an incoming water pressure greater than 80 psi (pounds per square inch).

They’re usually installed in the basement or wherever the water enters the home, usually near the water meter.

If your water pressure drops when multiple faucets are turned on, the fault may lie with the pressure regulator. 

To evaluate, attach a water pressure gauge to your pressure regulator, if there isn’t one already, and observe the readings.

If the needle fluctuates or shows a reading lower than normal pressure, your pressure regulator is causing the issue and needs to be replaced. 

Check for leakage in the pipes around the pressure regulator.

If there aren’t any visible issues, it doesn’t mean you’re off the hook. The regulator could malfunction due to other reasons, such as damaged components. 

Water pressure regulators and switches can also get clogged by debris and suspended particles in the water supply. Observe the pressure gauge and see if there is a delayed response to pressure, which may indicate a clog.

Clearing a clogged pressure regulator is easy, but if it does need replacing, they aren’t terribly expensive.

Problems with the well pressure tank 

Unlike homes with city water, which have a pressure regulator, homes on private well water have a pressure tank that maintains optimal water pressure in the home.

Finding problems within a pressurized water tank can be a tricky business.

Sometimes the inflatable membrane inside a pressure tank gets a pinhole puncture and fails to deliver the right pressure. If the pump cycle frequency has increased, then that’s probably the case.

A leak could also be surrounding the inlet, outlet, and pressure switch valves.

Apply soapy water to the connections and see if bubbles are forming. A leakage at this point not only affects your water pressure but wears out the pump as well. 

Sometimes, the pressure switch is attached too far from the tank. This could potentially disrupt the pressure due to excessive frictional losses. Experts recommend the pressure switch should be within five feet of the pressure tank. 

Lack of rainfall can also cause the water table to drop, which results in the pump extracting a considerable amount of air with water.

This can eventually lead to intermittent water pressure. If there are a lot of air bubbles and no apparent leakages in the pipe, then this might be the issue.

If you can’t find any obvious problem with the tank, read this guide to increasing pressure in your well’s pressure tank.

Leak in your water main

While a leak in one faucet won’t affect water pressure, a leak in the main might.

Find the location where water enters your home; this is the water main. It connects your home to the local water supply.

If you notice wetness around the main, a sinkhole, rust in your water, or an abnormally high water bill, it could be a leaky main.

This is a serious issue that could result in damage, so you should shut off the main right away and call a plumber.

How Do I Fix Fluctuating Water Pressure?

Now that you have your early diagnosis, it’s time to fix the water pressure in the plumbing system.

Besides simple fixes like cleaning your showerheads and faucet aerators, some of the solutions are a little more involved.

Of course, if doing odd jobs isn’t your cup of tea, you can always hire a professional plumber. 

Unclog the water system. 

You’ll need to narrow down the location of the clog. If the water pressure issue is limited to a specific sink or shower, the problem lies only there.

First, remove the faucets, fixtures, and showerheads using pliers, and clean them. Next, flush the aerator and small filters with high-pressure water or air. 

Do the same with shutoff valves under the sinks.

Disconnect the pipe connecting the main faucet and open the main shutoff valve. Let it run for 30 seconds. This is going to remove the debris and unclog the system.

If the pressure change occurs in only the hot water tap, flush the water heater. It will remove the debris from the system and restore normal pressure. 

In case you suspect clogging inside multiple pipes affecting the whole house, you have a little more work to do. A clear indication of this case is that water comes out fast and then slows down.

Unclogging pipelines in five simple steps 

This really is a job for a professional plumber, but I suppose it’s technically not impossible for someone to DIY it. Here goes nothing:

Step 1: Gather the necessary supplies. You need a bucket, a high-pressure water pump (kind of a big deal), pliers, and vinegar.

Step 2: Close the main supply valve. Open a nearby faucet (faucet A) and let the remaining water in the pipes drain. Keep it open during the rest of the process.

Step 3: Fill a bucket with three parts water and one part vinegar. Place one end of the pressure pump inside the bucket and attach the outlet to another faucet (faucet B). This could be any faucet inside the home. Remove the fixture and attach the pump to it using a simple connector. 

Step 4: Run the pressure pump. The high-pressure backflow will remove the blockage in the system. 

Step 5: Let the water drain from other faucets. Remove the pump. Reattach the fixture. Open all the faucets and the main shutoff valve.

Replace your pressure regulator.

For a leaky pressure regulator, you really should replace it — quick fixes will only aggravate the problem. You may even find they need to be replaced about every 10 years, or sooner.

Luckily, they aren’t expensive.

In fact, installation by a professional will cost more than the regulator itself, but if you try to do it on your own and damage your home with too-high water pressure, it will cost even more.

Maintain your well water pressure tank.

For those on well water, if the water flow from your tap is uneven and you have ruled out all the other possibilities, then a faulty pressure tank might be the culprit.

It’s important to follow a consistent maintenance routine for your pressure tank.

Start by checking the air pressure in the tank using a simple pressure gauge. 

To do that, first turn off the pump and close the main valve. Now, simply drain the pressure tank completely. Once done, attach the gauge to the Schrader valve, which is usually located somewhere at the top.

The air pressure should be 2 psi less than the cut-on pressure. In the case of a 30/50 setting on the pressure switch, the reading should be 28 psi. 

If it’s less than 28 psi, then this might be the reason your water drops abruptly. Use an air compressor to pressurize the tank. 

Examine the pressure switch as well. If the readings on the pressure switch are flickering or there is a delayed response, then the issue is with the switch. Either the valves surrounding the switch are clogged, or the switch itself is malfunctioning. 

Of course, it may simply be time to replace your pressure tank. They can last anywhere from 5 to 30 years, depending on the quality.

Luckily, you can switch out your pressure tank yourself, just follow this guide.

Final Thoughts 

Fluctuating water pressure is common in many households, so there’s really no cause for panic.

Simply diagnose the issue by ruling out each reason mentioned above. Once you get the idea of what’s causing your water pressure to drop, go for the possible DIY solutions.

These methods involve a little work on your part but can definitely fix the issue.

In cases where there is irreparable damage, such as broken or corroded pipes in the main water supply line, it’s better to let professionals take care of the problem. 

We at Drinking Water are committed to helping you solve your water woes by providing accurate and thorough information. For further help maintaining your drinking water, try these articles:

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