Why Water Pressure Drops, Then Comes Back

By: Jake Gallagher | September 18, 2023

Doesn’t it seem like the water system tends to break at the worst possible moment? You’re either in the shower, trying to wash a big load of laundry, or waiting for a huge list of guests for dinner, and suddenly your water pressure is nothing but a trickle. Oh wait, it’s back! Phew. But what’s going on?

If your water pressure drops then comes back, it’s likely due to clogged pipes, leaky valves, faulty pressure regulators, malfunctioning pressure tanks, or some fault in the municipal water supply.

I’ve researched ways to diagnose the problem and looked into possible fixes for each likely cause. So, before you go into a frenzy, relax and check out the possible solutions. 

Six Possible Reasons Behind Fluctuating Water Pressure

To find out what is causing your water pressure to fluctuate, you need to know the possible factors that can affect water flow around the house. Most of these circumstances can occur both in municipal water supply and private well systems. 

Upon inspection, if you find out that the problem isn’t in your water system, it’s best to call local authorities. Sometimes, maintenance in the municipal treatment plant can affect the normal water pressure in the surrounding area. 

Here are six likely causes of fluctuating water pressure in your plumbing system:

Leaky faucets 

When faucets and taps get old, they corrode and tend to leak. The same goes for running toilets. They do a lot more harm than just wasting water. For example, water leaks affect the pressure and flow rate of your entire water supply, especially if your house is constructed on multiple stories.

Due to continuous leaks, the pressure regulator attached to the water system begins to work on overdrive. This can cause unwanted water pressure fluctuations. 

All of this worsens when you use a private well system, as the submersible pump increases its cycle to keep up with the pressure requirement. The machine will eventually wear out, causing a big dent in your savings.

Defective pipelines 

Look out for bubbles. No, not the fun, soapy ones that we all like. Air bubbles in the water supply can disrupt the flow immensely. Air enters supply lines mostly through defective and cracked pipes. Even a small crack in a pipe would let air enter the system and cause leakage, which can exacerbate the issue. 

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 buildup, obstructing water flow. If not, clogging could be due to debris and gunk in a water supply system. 

Faulty water pressure regulator 

Have you ever wondered why storage tanks of city water supply are placed on the structure of extreme heights? That’s because designers use gravity to create ample pressure for the regular water to flow easily into the pipes. 

But this pressure is too high for your house water pipelines and it needs to be regulated using a piece of equipment called a pressure regulator. One such regulator is also present in your house. It’s usually installed in the basement or other point-of-entry of your water supply, near the water meter. For private well owners, the same is achieved by the pressure tanks. 

Pressure regulators, or water pressure-reducing valves, maintain about 60 PSI according to municipal codes. But you may notice fluctuating water pressure in your faucets due to leakages and corrosion. 

A faulty pressure regulator will not regulate the water pressure optimally in your taps and faucets. So, you need to figure out if your pressure regulator is performing its duty or not. 

One method of checking it is to attach a water pressure gauge with 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 if there is any leakage in the pipes around the pressure regulator. If there aren’t any visible issues, it doesn’t mean you are off the hook. The regulator could malfunction due to other reasons, such as damaged or busted components. 

In the case of a private well, you have to observe the “pump pressure switch,” which is present in front of a pressure tank. Pressure switches have factory default settings and maintain the overall pressure between 30–50 or 40–60 PSI. However, these switches can malfunction and cause your water pressure to drop unexpectedly. 

Your water pressure regulators and switches can also get clogged due to debris and suspended particles in the water supply. Observe the pressure gauge and see if there is a delayed response to pressure. 

If your water pressure drops when multiple faucets are on, then it’s clear that the fault lies either with the pressure regulator or tank. 

Pressure gauges and switches are cheap and easily available at any home improvement store. 

Damaged valves 

Valves regulate and direct the water supply inside your home. As a result, they are prone to corrosion and damage. And any damage to them leads to unexpected pressure drops due to aeration and leakage. Sometimes the threads of the valve wear out and need replacement. 

Here’s how you can check if your valves need maintenance. 

Start with the main shut-off valve, which must be located near your yard or basement. Make sure there is no apparent leakage. 

Next, check the stop valve under the sink. If it leaks or is left partially open, it can affect the water pressure.

Problems with the pressure tank 

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 it’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 must be an issue.

Excessive water use

Once you go through the early diagnostics, chances are you will find the reason behind sudden changes in water pressure. If not, ask your neighbors if they’re observing any changes in their water supply.

Sometimes if the house next door adds a swimming pool or a jacuzzi, it can adversely affect water pressure at your place. Call the local authorities if you think that is the reason.

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. Here are a few ways you can do so. Of course, if doing odd jobs isn’t your cup of tea, you can always hire a professional plumber. 

Unclog the water system 

If the water pressure issue is limited to a specific faucet and showerhead, 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 shut-off valves under the sinks. Disconnect the pipe connecting the main faucet and open the main shut-off 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 

Step 1: Gather the necessary supplies. You need a bucket, a high-pressure water pump, 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. Close all the faucets and the main shut-off valve.

Replace the damaged pipes, valves, and pressure regulator

Now, if you are facing leakages in pipes due to pipe damage, such as cracks, there are some ways to fix them. Apply epoxy resin or a sealing putty on the affected area. This is a temporary solution but can efficiently block any leakage. However, replacing the damaged pipe or pipes is best if they are more than ten years old. 

For a leaky pressure regulator, you really should replace it— quick fixes will only aggravate the problem. Worn-out valves also need to be replaced because short-term repairs won’t hold the pressure. You can either do it yourself or call a professional. 

Pressure tank maintenance

If the water flow in the tap is pulsating and you have ruled out all the other possibilities, then a faulty pressure tank might be the culprit. Start by checking the air pressure in the tank using a simple tire 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 tire 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. 

Water Pressure Drops, Then Comes Back—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.