Water Heater Dip Tube

Water Heater Dip Tube: What Is It & How To Replace

This guide on Water Heater Dip Tube, one of water heater parts will break down:

  • What is a dip tube?
  • How does it work?
  • Signs of water heater dip tube failure
  • Step-by-step instructions  to replace a dip tube
  • And more

Without further ado, let’s dive in. 

Table of Contents

Disclaimer: This post may contain affiliate links.

What Is A Dip Tube and What Does It Do On A Water Heater?

A dip tube is a plastic tube connected to the cold water inlet of your tank water heater. The dip tube extends from the cold water inlet to the bottom of your water heater’s tank.

As water is used, the dip tube draws cold water to the sensor on the gas valve. When the gas valve senses cold water, it opens and starts to heat the water in the tank up to the set temperature.

Generally, a dip tube serves the following purposes:

  • Channel cold water from the top to the bottom of the tank near the burner.
  • Heat cold water quickly.
  • Prevent the cold water from mixing with the hot water.

How Does A Dip Tube Work On A Water Heater?

You already know that a dip tube on a water heater directs the incoming cold water to the bottom of the tank. It ensures that the cold water entering the tank doesn’t mix with hot water at the top, allowing the heater to maintain a consistent hot water supply.

Here’s how a dip tube works:

  • Location: A dip tube on a water heater is attached to the cold water inlet at the top of the unit.
  • Function: The dip tube draws cold water down to the bottom of the tank, where the burner or the heating element heats the freezing water.
  • Efficiency: By channeling cold water down to the bottom of the tank, the dip tube helps to ensure that the hot water remains at the top of the tank, ready for use. 

What Factors Are Responsible For Failure of Water Heater Dip Tube?

Here are the six common factors that cause a dip tube on a water heater to go defective:

  • Age & Wear: The dip tube is constantly exposed to hot water and chemicals present in the water. Consequently, the dip tube deteriorated over time. It’s a common scenario on most old water heaters.
  • Material Defects: Material defects, for example, some dip tubes made of plastic, can brittle and break down because of manufacturing defects or prolonged exposure to high temperatures.
  • Chemical Reactions: Minerals like magnesium and calcium within water react with the dip tube and affect the dip tube. Constant exposure to high temperatures quickens the deterioration of the dip tube.
  • Sediment Buildup: Over time, mineral deposits or sediment buildup can accumulate on the dip tube and degrade it. This buildup can cause a crack in the dip tube.
  • Poor Water Quality: Hard water containing high mineral content can speed up the deterioration of the dip tube by causing increased scaling and mineral accumulation.
  • Corrosion: If the dip tube on your water heater is made of metal, corrosive elements like chlorine in the water can cause the dip tube to corrode. 

What Are The Symptoms of Water Heater Dip Tube Failure?

You will observe the following symptoms when the dip tube on your water heater fails or doesn’t function correctly:

  • Reduced hot water supply is a notable and common sign that indicates the dip tube is at fault.
  • Water temperature can fluctuate when the dip tube deteriorates. The hot water may turn cold suddenly and then warm up again.
  • Due to a faulty dip tube, you might experience a brief instance of hot water followed by quick cooling.
  • You will get small particles of white or gray plastics if the dip tube gets broken.
  • Because of a defective dip tube, you will get cold water from the hot water faucet. 

How To Replace A Water Heater Dip Tube?

Changing a dip tube on a water heater seems to be daunting. But if you have the right tools at your fingertips and guidance, you can effortlessly do this replacement task.

To replace a dip tube on a water heater, ensure you have:

Once you have these pieces of equipment, follow these step-by-step instructions to replace the dip tube on a water heater. 

1. Turn off the water heater first to ensure safety. If you have an electric water heater, shut the unit off at the circuit breaker. For a gas water heater, turn the gas valve to the pilot position or turn off the gas supply. 

Then, shut off the cold water supply to prevent new cold water from entering the tank.

2. Drain the water from the tank. I recommend you drain 5 to 7 gallons of water from the tank.

To drain the tank:

Draining Water Heater
  • Locate the drain valve at the bottom of the tank.
  • Attach a garden hose to the drain valve and place the other end of the valve to the nearest drain floor.
  • Open the drain valve by using a screwdriver. 

Alternatively, you can place a bucket under the drain valve and open the valve to drain some water.

3. Disconnect the cold water pipe from the cold water inlet at the top of the unit. You can use a pipe wrench to unfasten the cold water pipe from the inlet nipple. 

Disconnecting the cold water pipe with an adjustable wrench

4. Once you disconnect the cold water pipe, pull out the dip tube. If it’s fragile or broken, you need to fish out the remaining pieces from the tank. 

Loosening the dip tube with a pipe wrench

5. After pulling out the dip tube, it’s time to install the new dip tube. You can get the replacement part here on Amazon

6. Once you get the replacement part, prepare the dip tube for installation. Regarding this, cut the dip tube at the correct length. Line up the new dip tube with the old one and cut it. 

Sizing up the dip tube at the correct length

If the old dip tube completely deteriorates and there is no visible point, the new dip tube should land roughly three to four inches above the control valve. 

An easy way to measure this is to flip the dip tube around, put the threaded portion three to four inches above the control valve, and cut the other end flush to the top of the tank. 

Next, apply potable water-approved Teflon tape or seal into the lower threads. 

Preparing the dip tube with Teflon tape

Then, drop the dip tube into its place and hand-tighten it. Afterward, use an adjustable wrench with thinner jaws to finish the tightening task. 

Reconnect the cold water pipe to the inlet nipple and secure it by tightening it up. 

8. Refill the tank with water by opening the cold water supply valve. Inspect every connection to ensure there is no leak. 

9. Turn on your water heater. If you have an electric water heater, flip the circuit breaker for the water heater to the On position. 

On the other hand, turn on the gas supply and relight the pilot. 

Finally, operate the water heater for a few minutes to verify the unit heats the water properly, and there are no leaks. 

How Much Does It Cost To Replace A Dip Tube On A Water Heater?

The cost to replace a water heater dip tube is estimated to be between $250 and $300 if you hire a professional. 

Generally, the part (new dip tube) takes $20-$50 from your wallet, depending on the type and quality of the dip tube. You should count an additional $50 for other parts like Teflon tape and pipe dope. 

Why does the professional charge over $250 when the part costs only $50?

It’s all about time and labor. The biggest hurdle in replacing the dip tube is to get the nipple off from the water heater. 

However, the price may vary on location. 

You can reduce the replacement cost by DIY-installing the dip tube, provided you have the necessary skills, tools, and knowledge.

Otherwise, I highly recommend you hire a professional. 


Can I replace a dip tube myself?

Yes, you can replace a dip tube if you have the proper skills, tools, and knowledge. The replacement process includes turning off the water heater, draining some water, removing the old dip tube, and installing the new one.

How often should a dip tube be replaced?

A dip tube on a water heater typically lasts around 8-12 years, depending on water quality and usage. You may need to replace the dip tube often if a problem arises or due to lack of maintenance. 

Are all dip tubes the same size?

No, dip tubes come in various sizes and lengths based on the make and model of the water heater. 


A dip tube is an extended plastic tube that runs from the cold water inlet to the bottom of the tank near the burner or heating elements.

The dip tube directs cold water at the bottom of the unit, prevents the cold water from mixing with hot water, and keeps the hot water at the top of the unit.

Depending on the quality and maintenance, a dip tube typically lasts 8 to 12 years.

When the dip tube reaches its end lifecycle, you will notice these signs:

  • Reduced hot water supply
  • Inconsistent water temperatures
  • Short bursts of hot water
  • Plastic particles in water
  • Decreased water pressure
  • Cool water from the hot faucet

When you observe these signs of dip tube failure, understand it’s time to replace the dip tube.

Follow the step-by-step instructions I mentioned above to replace the dip tube. If you don’t have the right tools and skills, I highly suggest you hire a professional to make the replacement.

Do you have any questions related to the dip tube or water heater? Feel free to leave a comment below!

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