Thread: Water pipe noise

As I understand it, knocks are caused by two things.
1) Sudden stoppage of water flow which causes a loosely attached pipe to flex and knock against its supports.
2) Air in the lines which needs to be bled out.

For the first one you will need to feel along the entire length of the pipe while someone is turning the water on/off to ascertain the locality of the movement. While for number 2, I believe that the normal procedure is to yurn off thewater at the mains, open all taps full on starting at the one furthest from the mains and working towards the mains, leaving all taps wide open.
Turn back on mains a bit at a time. When full flow is achieved at the tap nearest to the mains turn that tap off and continue in the same fashion at all intermediar taps until you get back to the first one you turned on.

I hope one of these suggestions works.

PS arrestors are usually only used when the plumber can't work out where the problem is or when the problem area is too hard to get at.

Simonatra,
I also had bad hammer in our batroom/ laundry. I was under the impression that it is caused by a shock wave within the pipe by a valve shuts off too suddenly. The remedy is to install an arrester or replace faulty valve. If it happens when the tap is turned on then its not hammer and must be caused by that tap being faulty. I have this problem too after replacing the outlet valve in the loo I decided to put in a new inlet valve as well (ignoring the rule of If it aint broke dont fix it) Bloody thing shuddered so loud PITB. I turned down the inlet tap at the loo and also turned down the inlet at the meter to reduce the pressure and fixed the problem.

Hmm,

I have a similar problem, but only occurs with the mashing machine as it opens/closes the cold water inlet valve - especially when spray rinsing. It sounds like some bugger with a sledgehammer banging on the whole side of the house :eek:

I've tried venting the pipes, but without any success. Also, the feed pipes are 'buried' in the walls, so hard to get at without major surgery. Any ideas?

Steve,

You can buy 'water hammer arrestors' that you put in between the tap in your laundry and the hose to the washing machine.

Thanks Rowan!

Steve my first go would be to replace the valve in the coldwater tap with a special anti hammer valve. they have a little reservoir built into them that the backpressure works on somehow. Second attempt replace said tap. by the sounds of it if your pipes are concealed it is going to be hard to fit the arrestor.

This is a pic of the arrestor that I mentioned. It goes on the tap so you don't need access to the piping.


And also found a piccy of the washer that bleedin is talking about

Not sure that the anti hammer washer will help with the washing machine, the problem is the solenoid opening & closing suddenly that creates the shockwave. The tap/s to the W/M usually stay on.

Same deal with flickmixers - although at least you can make a point of turning them on/off slower.

The arrestor either in the wall or in line to the W/M would be the go I'd reckon.

Thanks for all the replies and assistance

I have bled the system to no avail all ready have a arrestor fitted to the washing machine. Unlike most I am having the trouble when any tap or mixer is turned on not off.

The plumber who I swap job skills was by yesterday and said he will have another look when he get a break

I had a bad water hammer on the washing machine even with a hammer arrestor that was fitted by the previous owner, similar to the one in Wood Butcher's post. I think perhaps the air expansion chamber was full making it useless.

I ended up getting a Doust anti hammer fitting that fits between the washing machine tap and the hose. Its an Aus (Perth I think) made fitting available from Bunnies for about $20 and apparently slows the water slightly with baffles that make the flow spiral. It solved my problem and I have fitted them to a couple of other places with the same results.

You can view then at the Doust website.

The tap/s to the W/M usually stay on.

Errr, I think a bad move. I have seen older hoses burst and flood houses while owners were away at work.

So, did you have a normal tap installed before the mixer , without the problem ?

Guessing, then it could be the mixer. Big guess.

I had a hammer problem recently with my laundry.....spent all one morning on my back under the house screwing in saddles along the pipes trying to secure the pipes better... The problem turned out to be just a washer on the tap itself. Faucet hammer the yanks call it.

The washer was shredded, and as soon as I put a new one in the problem was solved.....so thinking maybe your mixer has some kind of flow problem similar to the washer of mine ??? I don't know.

Goodluck, its frustrating eh.

Some might think this is pretty basic stuff.
http://www.factsfacts.com/MyHomeRepair/PipeNoises.htm

But I found it an easy read. Its after trying all my local plumber mates advice, I found this, and clued onto the problem being simply the tap washer.

May give you some ideas...

Jake (and all) after reviewing this thread I realise I have been incorrectly using the word Valve instead of Washer sorry folkes my mind was elsewhere (as usual). I'll be right after the operation.

Beedin Thumb don't be so hard on yourself as you are the one who is correct the the correct name is a jump valve