Can a bad check valve cause air in water lines well?

Author: Prof. Esta Rosenbaum DDS  |  Last update: Monday, November 10, 2025

A faulty check valve allows air to enter the system when the pump is off. Replace the check valve to prevent any backflow of air and water.

Can a bad check valve cause air in water lines?

If there are any leaks anywhere in the plumbing, a failed check valve can cause air to be pulled in when the pump shuts off and the water column above it flows backwards through the failed check. This pulls a vacuum on the plumbing and any small leaks can allow air in.

Why is there so much air in my well water lines?

Check your water pressure tank: Aging or damaged pressure tanks can sometimes lead to a buildup of air pressure in your lines. Drain the tank of excess water or consider replacing your tank if it's too old. Examine your well pump: A faulty well pump is one of the main causes of air in water pipes.

What happens when a check valve fails on a well?

When the check valve stops working, it is no longer able to prevent the well's pressure tank from sending water back down into the well as the pressure builds up. As a result, the pressure switch detects that water pressure inside the tank is dropping, so it turns the pump on again to pump in more water.

What are the symptoms of a bad check valve?

Common check valve problems include noise (water hammer), vibration/chattering, reverse flow, sticking, leakage, missing internals, component wear or damage. However, it is worth mentioning that normally the real cause is the wrong size, spring, and/or style for the check valve application.

No Water, Low Pressure, Air in Water lines. Here's Why! #1 Troubleshooting video

How do you know if you need a new check valve?

Signs It Might Be Time For an Early Replacement
  1. Water hammer: You hear a tapping or hammering sound, or the pipes are vibrating.
  2. There is leaking coming from anywhere on the valve, even as small as a pinhole or as big as a full-flow spray.
  3. It doesn't pass annual testing.
  4. Your water pressure is lower than normal.

What is the life expectancy of a check valve?

A metal disc pivots on a hinge or trunnion to prevent reverse flow. Most larger-scale check valves use this design due to their simplicity. With a life span of five to seven years, these valves are often a component that needs to be replaced frequently.

How long do well check valves last?

While typical component lifespans are application specific, manufacturers suggest metal and plastic check valves should be replace every 5-7 years whereas check valves manufactured from rubber may remain fully serviceable for up to 35-50 years.

How much does it cost to replace a check valve on a well?

How Much Does a Check Valve Replacement Cost? Depending on the size and kind of system, most homeowners spend between $135 and $1,000. Professional work costs between $100 and $400, while the gadget itself costs $35 to $600.

How to fix a bad check valve?

Step 1: Using a vice or an adjustable wrench, screw off and remove the check valve cap. Step 2: Once you get the cap removed, inspect the O-ring, cap and spring inside for any damage, wear or debris. Replace the spring as it is inexpensive and easy to do.

How do I bleed the air out of my well water system?

Can You Remove Air in Water Lines?
  1. Step 1: Turn Off the Main Water Supply. Begin by switching off the water supply at the main water valve (often found in the basement along the foundation). ...
  2. Step 2: Open Faucets in Order. ...
  3. Step 3: Flush All Toilets. ...
  4. Step 4: Turn the Water On.

Is it OK to have air in water lines?

Air in water lines is not usually a serious problem for your plumbing system. However, if left unchecked, it can cause severe water-flow and noise issues in your home. In extreme cases, it can also cause pipes to rust, harming their structural integrity and decreasing durability.

How do you flush air out of a water line?

While these sounds can be scary and seem like serious issues, the cause is usually quite benign. Most often, a loud sound coming from your pipes is caused by trapped air. By turning off your main water supply and running all faucets for 10-15 minutes, you force any trapped air through your water pipes.

Why am I getting air in my water lines with a well?

Over time, water well pressure tanks can become waterlogged, causing air to accumulate. Drain the tank to release the excess water, or replace the tank if it's old or damaged.

Can air pass through a check valve?

Air passes through the valve to the outlet. When pressure at the outlet becomes greater than at the inlet, together with spring pressure, the check device seals, preventing air from flowing back through the valve.

Can a check valve affect water pressure?

While they are simple and reliable, they can create more turbulence and resistance in the flow path, leading to a higher pressure drop compared to other designs. Y-type check Valves: The Y-shaped body design of these valves provides a more streamlined flow path, reducing turbulence and pressure drop.

What happens when a well check valve goes bad?

Common symptoms of a malfunctioning check valve for a well pump are as follows: Reduced water pressure. Cycling on and off often. A complete lack of water flow.

How do you know when a check valve is bad?

Symptoms of a Failing Check Valve

For example, failing check valves will start to vibrate and even lose some internal parts when problems begin to arise. Other symptoms of check valve failure include reverse flow and excessive component wear and damage. Check valves will also emit noises as they start to break down.

How much does a plumber charge to change a valve?

The average cost to replace a main water shut-off valve is $250 to $600, with most homeowners spending around $425 for the materials and labor.

Will a well pump work without a check valve?

Without a check valve, water would flow out of the pump and back into the well when it shuts off. The pump would be empty of water and unable to work without a user manually priming the pump.

How often should I flush my well pressure tank?

The tanks should be flushed semi-annually to remove accumulated sediments by opening the tank drain valve. These sediments could harbor and shield harmful microbes from chlorination should the well and home plumbing system require disinfection.

Do check valves need maintenance?

A properly functioning check valve allows liquid to flow in one direction and prevents reverse flow in the opposite direction. Proper installation and preventative valve maintenance are necessary to keep check valves in peak condition.

Do check valves get clogged?

If you notice that your shower isn't dispersing hot or cold water, it may mean that your shower check valves are clogged. This video will show you how to clean them and restore the performance of your shower. For more home advice, please visit our help center: https://support.signat...

When should a check valve be replaced?

Look for signs of corrosion, rust or mineral build-up. Replace the valve if there are extensive leaks or worn/broken pieces.

Do air check valves go bad?

Also referred to as one-way valves, check valves only allow air to flow in one direction. Check valves are found at the end of compressor leader lines and help isolate your air tank from your bags. Check valves can fail over time and cause a slight leak in your system. Luckily it's not a big deal, and it's an easy fix!

Previous article
How often should I change the water in my hydroponic system?
Next article
Can you test for Mould spores in the air?