How to fix squealing showerhead?

[NJ1]

We replaced a rail showerhead (because it's little plastic nubbins were busting open) with this bad boy: https://www.bunnings.com.au/flexispray-self-cleaning-handset-5-function-chrome-wels-3-star-9l-min_p0..., old showerhead off, new plumber's tape on outlet and showerhead, new one on, seemed like no drama. This showerhead screamed at us like a horde of demons from hell.

Google said limescale buildup is a common cause of squealing but the old showerhead (which would theoretically be dirtier than the brand new one) sounded just fine. Pipes all looked good, so we thought okay, probably just a faulty head and went and swapped it for this one: https://www.bunnings.com.au/mondella-chrome-overture-hand-shower-wels-3-star-8l-min_p0327091 Same deal, old head off, new plumber's tape, new head on.

Alas, this one too screamed at us, but the Mondella comes with a hose as well, so we thought hey, let's try changing the hose too, why not. No difference, still screaming. At this point we think maybe cheap showerheads just do that, though we can't fathom that our crusty old unidentified Caroma was terribly expensive. So we busted out the big bucks (for us) and bought this bad boy on CHOICE's recommendation: https://www.bunnings.com.au/caroma-luna-multi-function-hand-shower-wels-5-star-6l-min_p0180872

Alas, it is somehow even louder, and also makes the hose really stiff which doesn't seem like a good thing pressure-wise (maybe we tried to go too water-efficient?). We have an on-demand (instant) gas hot water system if that makes any difference.

Any help would be greatly appreciated by our eardrums.

[Nailbag]

Hi @NJ1 Most new plumbing fixtures work on reduced water pressures to save on water use. If the incoming pressure is too high, it can cause washers, cartridges etc to leak and with shower fittings a high pitched noise. New homes have pressure reducing valves fitted to the water mains inlet/meter. Renovated homes need one installed by a plumber. Since your old shower head didn't make a noise, but the new one does, this could be the cause. Experimenting by turning the mains tap down may provide the answer?

Regards, Nailbag

[TedBear]

I am following this with fascination, especially as none of the suggestions have so far led to a resolution...  My bet at this stage is on the tap washers going into oscillation, with the resulting sound being played by the shower head/s.  I wish I had an answer for you, but I haven't experienced this. I hope you find it soon.

[TedBear]

Hi again @NJ1 ,

another possibility came to mind on this issue...

You mentioned adding tape to the hose fittings and that the hose is now tighter after the latest head replacement...  I am wondering if a piece of that tape has accidentally been allowed to cross into the join and is partly blocking the water flow. It would then act like an instrument reed and cause a squeeling sound. 

It would be a good idea, if you haven't done it already, to remove the tape from both ends of the flexible pipe, since it is not needed there, due to the rubber seals keeping water from the threads. (If they don't, then the seals are faulty.) The tape could also  prevent the rubber seals from engaging firmly between the two surfaces as it could restrict how far the threads can be tightened.

[NJ1]

I removed the tape after MitchellMC suggested it was not supposed to need it, and indeed the instruction state only to use tape on the bracket/wall connection and not the bracket/hose or hose/head connection. Unfortunately it still leaks. I have hand tightened it as much as I can, and in fact can now no longer remove the hose from the bracket or the hose from the head so will have to enlist the help of someone stronger if we need to remove it to make a warranty claim, but we are going to test the mains pressure theory first when we have the opportunity.

[NJ1]

So turning the mains tap down has the same effect as just barely turning the taps in the shower on (which is what we have been doing to have semi-enjoyable showers). The pipe still leaks, and at a certain point the noise appears. The level at which the noise appears is still quite low, as in, not remotely what you would expect for a shower, and only just sufficient to trigger the required flow rate to get hot water from the instant system. Hopefully this provides some sort of insight?

We're going to look at replacing the washers next, but we need to wait until not so many people are home so it may be a couple of days.

[NJ1]

Update:

We tested the old showerhead on our in-laws shower in our shower and it sounds fine. No screaming. The only visible differences:

• No aerator (but we've taken the aerator out of our new one anyway with no success)
• Bigger hose>head passage, the old borrowed head has a passage nearly twice the diameter of the new one
• Bigger head>air nozzles, the old borrowed head also has larger outflow nozzles on the head itself

It stands to reason that the difference in either the passage or the nozzles is the relevant factor here, but as far as hose>head passage we have no way of determining the size without buying one and removing the aerator do we? What are the chances of even getting a new showerhead with a wider passage?

In addition, if the hose is supposed to be hand tighten and no tape, and is leaking from the threads, would this be a warranty situation?

[TedBear]

Hi @NJ1 , if the hose is leaking despite being tightened then it's likely that the seal is twisted or damaged. It will be essential to remove the hose connector and see. You may need to put tape over it and over the teeth of a wrench to loosen it without scratching it. Is it possible to take the new set-up to your in-laws and see what happens there? That could tell you a lot.

[MitchellMc]

Hi @NJ1,

I'd consider returning the showerhead just because of the screaming issue; I'm sure our team will do their best to assist. The connection leaking would be another reason to return it. If the team can't resolve the issue, such as a twisted washer, they'll swap it for another unit or return it under warranty. However, we'd most likely return the unit purely due to the noise issue.

I'd head into your local store and speak with the Plumbing Expert about the issues.

Mitchell

[NJ1]

We have achieved victory of the screaming hell demons!

We took the Mondella back and exchanged for one that was as close in design to the one the in-laws have as possible which was this one: https://www.bunnings.com.au/flexispray-5-function-pulsar-hand-shower-wels-not-star-rated-star-7-5l-m...

It's absolutely perfect, no screaming no matter how high we turn the tap, and probably even quieter than the old one. The only adjustment we made is we haven't used the washer with an aerator (it comes with a couple spare normal washers so we used one of those) and we are still using our original wall bracket (the one that comes with the head has an aerator attached).

Because the aerator isn't in the base of the handle I was able to see that passageway through the packaging, and it is definitely bigger than the one on the Mondella. It also has larger nozzles than the Mondella (and no leaking pipe!).

I'm sure it's some weird combination of our setup that caused the drama, but we are finally able to shower in peace, so I'll take it.

[MitchellMc]

Awesome work @NJ1! I'm so glad you've resolved that issue. 

I've already provided your feedback to the suppliers, and I trust if this is anything other than a unique outlier, they'll investigate further.

Many thanks for your patience and well done. Enjoy those relaxing showers!

Mitchell