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What Causes the Water Pressure Starts High Then Drops?

Water Pressure to go up and Down

Water pressure going up and down is a problem for some people. The cause of this issue can be hard to figure out.

In this article, I will give you a few reasons why water pressure starts high then drops.

I had to go through this plumbing issue and discovered and fixed such a water pressure issue at my home.

It is a common problem in many homes. The reasons can be many, but in this article, we will discuss the most common reasons that may cause this issue.

What Causes Water Pressure to go up and Down?

The most common reason that causes the water pressure to start high then drop is the water pressure in the water pipes is higher than the pressure at the tap’s point.

It could happen for many reasons but the most common are – 

  • The water pressure coming from a partially clogged pipe, 
  • A minor crack on the pipe,
  • Faulty valves, or 
  • A malfunctioning pressure regulator.

As this problem is commonly located somewhere inside your water supply line, let’s investigate everything that may cause water pressure to go up and down.

1. Partially Clogged Water Supply Pipe

Partially Clogged Water Supply Pipe

If you see high water pressure for a few seconds or minutes, then the water supply pipe might be partially clogged. It could be caused by the partial clog of the elbow joint or t-joint pipes, which are located at the connection between the main water supply line and faucets.  

How Can You Be Sure? 

Try to turn on every faucet in your home to check if there is any unusual gurgling sound. If you hear any gurgling sound coming from the faucets, then you know that it is partially clogged.

However, sometimes your water supply pipe could be fully clogged and in that case, you will not hear any strange noise and no water will come through when you turn on all your faucets.

When the water reaches the clog, it will lose force resulting in a sudden loss of water pressure. But, essentially, the water will keep moving through the pipe. And that movement of water will restore pressure. 

So in this situation, if no water flows out of the faucet for a couple of seconds, the standing water will build up behind the clog until it finds its way around it and rushes through the pipe toward the faucet, and the pressure returns to normal after a few seconds.

Why Water Pipe Get Clogged?

Water supply line clogs are formed when minerals in the water expand when they come into contact with your pipes’ metal. This flushes the minerals deeper into the pipe, creating a clog that can be tricky to trace at first. Small, pin hole-size clogs can lead to large problems if they go undetected for too long.

How to Fix Clogged Water Supply Pipe?

Clogged Water Supply Pipe

It is advisable to call a plumber in case there is a fully blocked main supply line because this type of clog cannot be solved by doing it yourself.

However, if there is only partial blockage, here are the instructions to fix it: 

Step 1: Turn off the main water supply valve and make sure there is no water inside the pipe, as you only need to open the faucet and let the water flow out. 

Step 2: Find a pail and fill it with hot water. Then, pour some vinegar into it.

Step 3: Use a toilet plunger and plunge it into the pail for about 30 seconds.

Step 4: Unscrew and pull out any mineral deposits from the faucet. 

Step 5: Flush the pail down with water for about 10 minutes, slowly opening and closing your faucet so that it flows out of the pail perfectly. 

Step 6: Turn on your water supply and check if your problem got solved or not.

2. Minor Fracture on the Water Supply Pipe

Fracture on the Water Supply Pipe

Some professionals think that a minor crack on the pipe lets air inside the pipe, thus creating bubbles in the water. The bubbles will then force out some of the water, lowering the water pressure.

This can happen any time you open a faucet to let water flow. The air that comes into the pipe creates a barrier, slowing the water’s progress, thus resulting in loss of water pressure.

However, the air in the water supply pipe must go somewhere and when it does, the water pressure comes back to normal.

So, here’s what goes on behind the water pressure drops then come back –

  • Cracked water pipe let air in
  • Air creates a barrier in the water pipe
  • Water pressure get dropped
  • Air Leves while faucet open
  • Water pressure get back to the normal state

The best way to see if something is wrong with your pipes is to stay vigilant. If it doesn’t seem like enough water is coming through, check the small bits first before heading out to the larger parts of your plumbing system.

How to Fix Minor Fracture on the Water Supply Pipe?

It is advisable to call a professional plumber because this type of issue can not be solved by doing it yourself.

3. Faulty Shut Off Valves

Faulty shut Off Valve

Faulty valves could be the cause of the water coming out fast then slowing down. Since they regulate the flow of water and the pressure, there could be problems like this when they are old and rusty.

Faulty valves can cause the water pressure to drop after a few seconds in one or more of your faucets. These faulty valves don’t fully open when you turn on the faucet; instead, they slowly leak water. 

However, as the valve regulates the amount of water that goes through the pipe, and there could be a sudden drop in water pressure since the valve might loosen up too much.

As the valve started regulating the water flow properly after a couple of minutes, the water pressure returned to normal again.

How to Fix Faulty Valves Issue on the Water Supply?

Fix Faulty Valves Issue

It is advisable to call a professional plumber because it is not that kind of task you may do yourself, especially if you do not have any previous experience working with such works.

However, there is nothing wrong with trying to fix this yourself. If you are like me and want to get your hand dirty, you can buy a new valve and try to install it yourself. 

4. A Malfunctioning Pressure Regulator

If the pressure regulator is not working properly, then that can cause a change in water pressure. The most common cause of water pressure changes in the system is pressure regulator malfunction. 

The pressure regulator is a device placed on the incoming water supply line to reduce the water pressure. It keeps the water at a constant rate so that there are no sudden changes in the flow of the water.

A malfunctioning pressure regulator can cause the water pressure to get high then drop, which creates just this problem of fluctuating water pressure. 

A malfunctioning pressure regulator can cause the water pressure to get high then drop because it is causing a surge of water to come through your plumbing system. 

How to Fix Malfunctioning Pressure Regulator on the Water Supply?

It is also not advisable that you do it yourself but still you can try…:)  

Final Words

Low Water Pressure

There are many reasons that your water pressure might start high then drop. However, water pressure in your home is very important, so when it starts to drop, you need to know why this is happening and what can be done about it.

The consequences of these kinds of problems vary greatly, but the easiest way to resolve them is to prevent them in the first place.

Regularly do a complete analysis of all parts in your water-pressure system in order to identify the early signs of a possible breakdown. 

This will allow you to have your broken appliances replaced in a timely manner, so you don’t have to deal with unexpected inconveniences when you least expect them.