How to fix regular pipe shudder?

[QldMagpie]

I have a single-storey house in Sippy Downs Qld that is about 20 years old. I have a rainwater tank with an Onga Watermark Water Switch serving an Onga SMH45 water pump. The tank water serves two toilets, two garden taps and the washing machine.  I have lived here for just over 18 months. We noticed intermittent pipe shuddering/hammering when either toilets or the outdoor taps were used, and this seemed to be fixed by replacing the toilet inlet valves and changing the toilet inlet taps to ¼ turn ones.

We recently had work done in our ensuite and kitchen, including relocation of some pipes and replacement of taps etc. Since then the shuddering has returned intermittently when the toilets are flushed and also when the new Grohe kitchen mixer is turned on (generally when set for cold water).

I have followed instructions for removing air from pipes,  but cannot seem to stop the pipe noise.

Interestingly, in all of this, there has been no pipe noise whatsoever from the washing machine.

I am wondering whether a hammer arrester would help, and I am keen to hear recommendations and suggestions.

[AlanM52]

Hi @QldMagpie,

You have two systems.

Tank: two toilets, two garden taps and the washing machine.

Mains: ensuite and kitchen plus the rest.

I suspect the recent plumbing works has introduced a mechanical issue that is affecting both the Tank circuit and the Mains circuit.

I say this because on one side the toilets are effected and on the other side the kitchen tap - crossover.

You could try checking each tap by opening and then very slowly closing the tap and at some point (resonate point) the shuddering should noticeably increase which hopefully will help to track down where it's coming from - the area.

Maybe loose clamp(s) or pipe to close to something like a wall stud etc.

It could be the washing machine is ok because it is further away maybe at the end of the line.

Cheers

[JacobZ]

Hi @QldMagpie,

A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.

It's fantastic to see @AlanM52 has already jumped in with some advice. My thinking is on much the same lines.

The fact that the shuddering disappeared after replacing the toilet inlet valves and taps, but returned after plumbing work in your ensuite and kitchen, suggests the recent work may have introduced new factors. This could include longer, or less-secured pipe runs, or a change in water flow dynamics. 

The cold side often causes more noticeable noise because of higher flow rates or less resistance. Interestingly, your washing machine doesn’t cause any issues — likely because it fills gradually using internal solenoid valves and may be connected to a more stable part of your plumbing system.

You could try installing Douststop Anti Hammer Water Control Valves on the inlet for the toilet and sink mixer where you are experiencing issues. This is a good starting point that wouldn't require the assistance of a plumber.

If the problem persists, you should try to find the source of the sound. Turn off all the taps and intermittently test. By following the sound, you may be able to locate the source of the shuddering. Adding additional pipe clips to the pipe run could help with the issue.

If you have no luck, I suggest you contact a plumber for assistance.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[AlanM52]

G'day mate,

RE:  likely because it fills gradually using internal solenoid valves.

One word can be used to describe the physical action of a washing machine water solenoid valve - Brutal.

All the washing machines I have repaired in the past have 'hard' solenoid valves.

Maybe these days they have changed to 'soft' solenoid valves.

(Similar to power tools that now have soft start motors).

One of the common problems I have come across is a ruptured/split water valve diaphragm due to the instant open/close action of the valve and  almost always it is the hot water side. I always recommend depressurize the hose lines.

When the washing is done and the taps turned off (they should be) the hose lines are still under pressure.

Set the machine to start a wash cycle... the valves will thump... and shut down.

Cheers