What Should I Know About Water Hammer

You know that irritating, loud, banging and vibrating noise that you hear when you turn off the tap? It’s what we call a water hammer.

Water hammer occurs when a valve is suddenly turned off which causes the pressure from the gushing water to suddenly stop. This high pressure then causes hydraulic shock waves that reverberate throughout the pipes thereby causing those loud vibrating noise that you hear.

We would need to differentiate though if the sound that you hear is from a water hammer or from trapped air inside the pipes. One simple way to do this is to determine when you hear the sound. If you hear the sound after you have turned on the tap, then that is trapped air inside the pipes. But if you hear the sound after you have turned off the valve, then definitely that is a water hammer.

Water hammer may only sound like a simple annoyance but we should not take it lightly. Water hammer can lead to a serious plumbing issue and can lead to a leaking pipe or a burst one. The most common valve that causes water hammer to occur in your homes are the valves in your washing machines and dishwashers. These valves were designed to deliver more than the usual amount of water to the water fixture that they are connected which means that there is a higher water pressure coming from the flowing water on these taps. So when you suddenly close these valves, you now have the recipe for a potential water hammer.

Normally, when you shut off your valve or close the taps, the water pressure is diverted into the air chamber on the vertical pipes to cushion the effect of the water pressure rushing in when the water is suddenly shut off. The vertical riser, therefore, helps to minimize the water pressure and dissipates it before it reverberates throughout your piping system. But over time that air packet is lost and that’s when a water hammer occurs.

In order to resolve and fix any water hammer issues, you would need to restore the air packet on the vertical risers on your taps. You can try fixing this by opening the highest tap in your house and let it run for a while in order to remove the air inside the pipes. If this will not resolve the problem, you can try shutting off the main water meter and letting all the water drain from your property. Once you turn the water back on, this would let air back into the air chambers on the vertical risers of your piping system. If the water hammer is caused by very high water pressure, you would need to install a pressure limiting valve so as to control the water pressure going inside your house.

The Hot Water System is one of the essential appliances in every Australian household. They can either be gas, electric, and solar powered or a combination of these.

Hot Water Systems accounts for at least 21% of the energy consumption of most Australian homes. The majority of the hot water consumed is in the bathroom with a third of it being used in the laundry area and the rest are used in the kitchen area. You definitely would not want to wake up on a cold winter day with your hot Water System not working properly.

So here are some things that you can check if your Hot Water System is not working:

1. If you are not getting any hot water coming out of your taps, the first thing that you need to check is to make sure that you have cold water running out from the taps. If there is cold water, then this problem is something related to your hot water system. Check the isolation valve on your Hot Water System. It’s usually the yellow or red handle on the side of the water intake.

Plumbing Repairs | Plumbing and Electrical in Port Stephens
Pressure limiting valve installation using a B-press machine

What are the types of pressure limiting valve available in the market?

  • Direct-acting – The simplest of PLVs, the direct-acting type, operates with either a flat diaphragm or convoluted bellows.
  • Internally piloted piston-operated – This type of PRV incorporates two valves-a pilot and main valve-in one unit.
  • Externally piloted – In this type, double diaphragms replace the piston operator of the internally piloted design

It’s best though to do preventive measures in order to prevent water hammer from happening in your piping system. One way is to replace your flick type taps that close very quickly with the soft close taps. Another way is to install water hammer arrestors. They might be costly though since you would need to attach them to all your mixer taps.

Water Tank Parts | Plumbing and Electrical in Lake Macquarie
Water hammer arrestor

Water hammer can cause pipes to burst and leak so if the problem persists, it would be best to call your local plumbers to check on the problem before it gets worse.

If you got any electrical and plumbing problems don’t hesitate to call us at 13 10 91 to fix the problem right away.

here is another article that you may find interesting in regards to “Why do my lights flicker?”

At The Plumbing and Electrical Doctor we have made these articles downloadable to PDF for our customers convenience

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