That banging or hammering noise inside your walls after a tap or water is turned off is what’s known as water hammer, or the technical term is ‘hydraulic shock’. Water hammer is a sure sign that all is not well with your plumbing. Like all plumbing issues, prevention is better than cure – water hammer needs to be fixed before your pipes leak or burst.
What is it?
While water hammer can happen when you turn off the shower or a normal tap, it’s more common in bigger pipes, such as those found in washing machines, dishwashers and toilets. These appliances have a valve that opens when they are being filled up and closes very abruptly once the appliance is full. As you can imagine, when a washing machine is filling up there is a significant amount of water moving at high speed through the pipe.
When the valve suddenly shuts off, the momentum of the water causes the pipe system to jolt or shudder. If there’s a problem with the air pressure in the pipe or loose mounting straps, the pipe will shake and bang against the wall or other pipes. This is the cause of the loud banging sound.
Why does it happen?
Water hammer happens in new houses but is more common in older homes where worn-out pipes absorb less of the shock and mounting straps may have loosened over time. The longer the problem persists, the more damage is being done to the pipes and mounting straps that hold them in place. It’s important to stop a water hammer before your pipes leak or burst.
How to fix a water hammer
There are a number of possible solutions to the problem of a water hammer. The first you can probably try yourself:
- Turn off the water at the main.
- Turn on all taps in the house and flush the toilet/s. Its best to start with the highest plumbing outlet in your home.
- Let all the water drain out of the taps and wait for 30 minutes.
- Turn the water main back on.
- Let the water run from all taps for 5-10 minutes.
- Then turn off the taps, starting at the lowest outlet. (Toilets will automatically fill.)
- Once all taps are off and toilet/s filled, flush the toilet or do a load of washing to check for water hammer.
If that doesn’t work, let our plumbing expert help you out.
Melbourne homeowners call experienced master plumbers, the right professionals to call about banging pipes and other plumbing problems. They’ll be able to resolve this issue with a quick visit to your home.
What can the plumber do?
To help you understand how they will address the problem of water hammer, here are some typical solutions:
- Fit the pipe closest to the valve with a shock absorber.
- Replace a vertical pipe with a spiral of copper pipe.
- Install a valve that reduces pressure on the water supply line.
- Fit water heaters with an expansion tank on the cold water side.
- Re-fit house with larger 3/4-inch pipes so that the water flows more slowly.
Different situations can call for different solutions. Sometimes, water hammer can also be caused by broken taps or valves, loose pipes, steam heat, and gurgling and banging caused by problem hot water systems. The best course of action is to contact your trusted plumbers who can perform quality emergency or routine repairs, renovations and adjustments to fix your banging water pipes once and for all.