Do I Need a Water Hammer Arrestor for the Dishwasher and Washing Machine?

Water hammer arrestors are devices installed in appliances with fast closing valves. The arrestors absorb the shock produced when water valves shut off quickly. As a result, water hammer arrestors prevent the machines from being permanently damaged. 

Do I Need a Water Hammer Arrestor for a Dishwasher?

A dishwasher is one of the appliances with fast-closing valves. Once the cycles are complete, the device stops, and water flow stops too. Due to the sudden stop of water flow then, your dishwasher can get jammed and stop working entirely. That is where a water hammer arrestor comes. 

Hammer arrestors will absorb the sudden shock produced when the water shuts off. Water hammer arrestors are ideal for copper and steel pipes. 

Do I Need a Water Hammer Arrestor for a Washing Machine?

A washing machine is also a quick closing valves appliance. You will need to control the shock generated when the water flow stops suddenly.

Do Dishwashers/ Washing Machines Need a Water Hammer Arrestor?

All appliances with fast closing valves should be protected from jamming due to the sudden stop of water flow. Some machines use an air gap. However, a hammer arrestor is the most effective shock absorber device. 

When installing a dishwasher, a washing machine, or an ice machine, you should invest in a quality hammer arrestor. 

A water hammer arrestor is a device used in fast closing valves appliances. You, therefore, do not need an arrestor in your shower.

Where Do You Put the Water Hammer Arrestor in the Dishwasher?

If your dishwasher has been producing a creaking sound when shutting off, it means experiencing a water hammer. Water hammer arises when the pressure in the hoses is compromised when the valves shut off suddenly. 

Therefore, you should install the water hammer arrestor directly into the valves. However, other manufacturers advise you to install the hammer arrestor at the back of the dishwasher to protect the hoses. 

Where Do You Put the Water Hammer Arrestor in the Washing Machine?

A washing machine also has hoses and valves that shut off when water flow stops. The water hammer arrestor is installed in the valves or behind the washer to protect both the valves and the hoses from getting damaged. 

Are Water Hammer Arrestors Necessary?

You can use your dishwasher or a washing machine without the hammer arrestor. However, to help prolong the life span of your appliance, you will need to install a hammer arrestor.

A hammer arrestor eliminates the noise produced by your appliance when shutting off. This is because the device balances the pressure used to shut off the appliances protecting them from cranking.

You should ensure you are using a hammer arrestor in your appliance. Learning how to install the arrestors is not very hard. You can use the following video for introductory purposes. 

Install Water Hammer Arrestor in a Dishwasher

A water hammer arrestor should be installed between the shutoff valves and the water supply line. The hammer arrestor introduces a cushion of air that aims at balancing the pressure of water. So you should install it properly for it to fulfill its purpose. 

Below are the tools you need to install a water hammer arrestor

  • Pliers
  • Adjustable wrench
  • Pipe wrench

You will also need a high-quality water hammer arrestor. 

Step 1: Locate which valve is producing noise

If your plumber did not install a water hammer arrestor, you could still install it in an existing dishwasher. 

Locate which valves produce huge noise which is caused by water hammer. Sometimes the noise is caused by an increase in pressure in your supply line. You should measure the pressure of your water to determine if it’s the cause of the banging noise. 

If the water pressure is above 75psi, then that’s the cause. Maintain the pressure around 75psi. You should go-ahead to install an arrestor if the pressure is normal. 

Step 2: Shutoff the water supply and disconnect the hoses from the valve

Before starting any DIY project, you should ensure the dishwasher is disconnected from the supply and electric lines. Be careful not to lose some connectors, such as washers used in a dishwasher. 

Step 3: Connect the water hammer arrestor at the end of a supply valve

Onto each supply valve, thread the hammer arrestor until its hand is tight. You can use the pliers to tighten the valves until you feel some resistance. 

Tightening too much might cause the arrestor the break. 

Step 4: Connect the water hammer arrestor to the hoses

Connect the dishwasher hoses to the hammer arrestor and ensure they are tight enough. Match the hot water hose to the hot water supply line. 

Step 5: Turn on the water back 

After you are done with all the installations, you should turn on the water back and test if the water hammer arrestor has solved the issue of the cranking noise. 

To know the arrestor is working as expected, little to no noise will be produced when shutting off the dishwasher.

Install a Water Hammer Arrestor in a Washing Machine

Installing a water hammer arrestor in a washing machine is not any different. Both appliances have shutoff valves and a water supply line. The main difference is the washing machine has a hot and cold water supply line. You will therefore need to have an extra hammer arrestor. 

The water hammer arrestor can be connected directly to the valves or the washing machine. This depends on the manufacturer’s specifications. Otherwise, installing a hammer arrestor in a washing machine is different from installing one in a dishwasher. 

How Do I Stop the Water Hammer in My Dishwasher?

Water hammer arises when water flowing under high pressure suddenly stops. As a result, the valves and the pipes might experience shock, which might interfere with your dish’s efficiency. To prevent this from happening, you should use a water hammer arrestor. An arrestor introduces a cushion of air that deals with the sudden stop of the water flow. 

Some people use an air gap to stop a water hammer; however, a water hammer arrestor is effective for this job. 

How Do I Stop the Water Hammer in My Washing Machine?

Like the dishwasher, you can stop the water hammer in a washing machine using an arrestor. The arrestor installed between the faucets or on the supply line valves will manage the shock produced when water flow stops faster. 

Where is Water Hammer Arrestors Required?

Water hammer arrestors are installed in appliances that have a fast shutoff valve. These are appliances like a dishwasher, a washing machine, and an ice machine. 

Slow shutoff devices such as showers do not need an arrestor.

Arrestors are also ideal for copper and steel pipes, not plastic and PVC pipes.

Are Water Hammer Arrestors Required with PEX

PEX is a rigid yet flexible pipe. Therefore, in the case of a water hammer in your supply line, PEX pipes are prone to be affected, and the tube may be disconnected. To prevent this, as long as PEX pipes are used with a dishwasher or a washing machine, you will need a hammer arrestor. 

Ensure the hammer arrestor is threaded properly on the male thread of the valve and use materials like Teflon tape when connecting the arrestor to PEX pipes. 

Conclusion

Installing a water hammer arrestor in your dishwasher or washing machine is not very complicated. However, you will need to know the measurements of both the shutoff valves and the pipes. This is for compatibility. 

Your arrestor might be damaged and need a replacement. To know if your appliance needs an arrestor, listen to the sound made when switching off the machines. If the noise is loud, you need to install a water hammer arrestor.

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