Flexi tap connectors. Burst.

[rufusgti]

Glad you checked them and found a wrong un.
I'm not qualified to say how accurate this may be. But I told a plumber friend of mine about the burst Flexi and he immediately said
"I bet it was the hot tap, closest to the combi?"
He was bang on. Apparently the closest tap gets the hottest water, the heat cycling wears out the rubber hose quicker. Makes sense. So maybe that's where too check first.

[princeperch]

Yep that would figure. this is a hot tap and it's almost next to the boiler (which is boxed in in the bathroom).

I can't see any other signs of fatigue on any other of the pipes. But this one is getting swapped over pronto.

[dhutch]

That's interesting too, but makes sense. Would make a lot of sense to have a date on them. Given you cant see the rubber for the overbraid.

I had a pair on a radiator in my old house, which they are not rated for, didnt really get hot. Rubber has swelled into a right mess, replumbed in 15mm copper and the room was hot again, my lodger was most greatful!


Daniel

[Black_S3]

kev1974 said:

If they were that fragile I'd have expected home insurance to be including a question about whether there were any flexi connectors in the home and if so quoting a higher price. They don't ask about them so that suggests to me they aren't bothered and that in turn suggests they don't pop often.

I think a lot of home insurance companies do have clauses around flexis.... not seen anything about taps but definitely seen clauses about toilets connected with flexi.

[dhutch]

Black_S3 said:

kev1974 said:

If they were that fragile I'd have expected home insurance to be including a question about whether there were any flexi connectors in the home and if so quoting a higher price. They don't ask about them so that suggests to me they aren't bothered and that in turn suggests they don't pop often.

I think a lot of home insurance companies do have clauses around flexis.... not seen anything about taps but definitely seen clauses about toilets connected with flexi.

Or that they think it would be unpalatable and or unenforceable... Who knows if their bath taps are on flexis? Or the age of them? What the plumber does? Etc.

[anonymous-user]

Interesting thread... and worrying too.

It seems the issue is with the metal braided hoses corroding.

I recently did some underfloor plumbing in a highly inaccessible location using pvc pushfit type connectors so I’m assuming these aren’t at such high risk as they have no braid to corrode?

I assume also the braided ones are fine if in a corrosion free environment?

Any thoughts or am I deluding myself ?

[Pheo]

dhutch said:

That's interesting too, but makes sense. Would make a lot of sense to have a date on them. Given you cant see the rubber for the overbraid.

I had a pair on a radiator in my old house, which they are not rated for, didnt really get hot. Rubber has swelled into a right mess, replumbed in 15mm copper and the room was hot again, my lodger was most greatful!

I’m not sure any of them are designed for or rated for radiator / central heating anyway: that’s a majorly different use case to running the hot tap a couple of times a day!

[dhutch]

Pheo said:

I’m not sure any of them are designed for or rated for radiator / central heating anyway: that’s a majorly different use case to running the hot tap a couple of times a day!

Oh, crappy bodge of the highest order, inhereted with the house which was owned by a 'builder' of the horse riding kind!

MikeStroud said:

Interesting thread... and worrying too.

It seems the issue is with the metal braided hoses corroding.

I recently did some underfloor plumbing in a highly inaccessible location using pvc pushfit type connectors so I’m assuming these aren’t at such high risk as they have no braid to corrode?

I does appear that often the failure mode is often the braiding, which appear odd, but I personally wonder is the root cause is actually the rubbish perishing, starting to weep, and allowing the low grade stainless used to degrate.

Unlike say Hep20/JG push fit, most of these flexis are brand-less bargain basement spec items, which in terms of spec/life makes a huge difference. I am sure JG use the best grade o-ring they can!

The other option, which seems less common, is the pvc based hoses, similar spec to that used for washing machines.
Slight less flexible, not so common, often cost a bit more, but also usually brand-name and nice feel to them.
https://www.johnguest.com/speedfit/product/15-22mm...


Daniel

[MJNewton]

dhutch said:

I does appear that often the failure mode is often the braiding, which appear odd, but I personally wonder is the root cause is actually the rubbish perishing, starting to weep, and allowing the low grade stainless used to degrate.

The Australian article linked to earler goes into some detail about the most common root cause, including:

Australian Article said:

Based on analysis of burst flexible connectors, it seems to be the braided stainless steel component of the product that is failing.

The rubber tube lining in flexible connectors expands when pressurised and the braided layers of stainless steel are designed to prevent this tube from further expansion. If the stainless steel fails, the rubber inner core will expand to a point where it bursts.

“This is primarily caused by a slow leak at the connection point, which runs down the hose into the braided stainless steel and leaves a deposit of chloride. Over time these chloride levels increase in the deposit creating pitting corrosion. The pitting locally reduces the cross-section of the wires to a point where overload failure occurs (due mostly to the hydrostatic water pressure),” says Metropolis Solutions forensic plumber Russell Kirkwood.

[...]

“Stainless steel isn’t impervious to corrosion and can become vulnerable when put through certain conditions. However, the stainless steel braiding is appropriate for its function and it’s the leakage at the connection that is the issue. You can always trace a leak path in these hoses and all the ones I’ve seen have had a leak path at the connector.”

The situation reminds me a little of spontaneous explosion of high pressure bike inner tubes. The tube (== rubber hose) is often blamed when in actual fact it is the tyre (== braided steel) coming away from the rim and being no longer able to contain the tube which in turn expands and ruptures.

dhutch said:

The other option, which seems less common, is the pvc based hoses, similar spec to that used for washing machines.
Slight less flexible, not so common, often cost a bit more, but also usually brand-name and nice feel to them.
https://www.johnguest.com/speedfit/product/15-22mm...

We've got that type of tail (the hose aspect at least; I don't recall it being pushfit) and am wondering if they might be a better bet than the more-conventional braded hose type for our new kitchen in light of this discussion. That said, the braded hoses have been supplied with the tap (a Franke so whilst not top of the range it's not at the bottom either) and I wouldn't want to inadvertently end up putting myself in a worse situation by choosing to go my own way.

[princeperch]

Well the older flexible pipes have been swapped over today. The hot tap one was in quite a state and the rubber was poking through in one place !

I also think there might well have been a weep from where the tap connects with the pipe which might have aided the corrosion

[Crumpet]

dhutch said:

The other option, which seems less common, is the pvc based hoses, similar spec to that used for washing machines.
Slight less flexible, not so common, often cost a bit more, but also usually brand-name and nice feel to them.
https://www.johnguest.com/speedfit/product/15-22mm...


Daniel

I’ve been using the Speedfit flexis because they did feel much better quality than what was supplied with the taps. Also a doddle to fit, but then I’m a fan of pushfit in general - I guess I’ll change my mind when I have my first leak.

Anyone using the Honeywell or Samsung leak detectors? Been tempted to pick some up.

[dhutch]

MJNewton said:

The Australian article linked to earler goes into some detail about the most common root cause, including:

Fair enough, should have read it in more detail, ok yes ok.
- Stainless gets wet, fails, rubber fails outwards through the hole.
- All of which, typically, happens faster than the rubber failing.

Presumably if you keep the stainless dry, eventual the rubber will fail, but maybe much later.

princeperch said:

Well the older flexible pipes have been swapped over today. The hot tap one was in quite a state and the rubber was poking through in one place !

I also think there might well have been a weep from where the tap connects with the pipe which might have aided the corrosion

Looks like a near-miss and a half to me that!

Crumpet said:

I’ve been using the Speedfit flexis because they did feel much better quality than what was supplied with the taps. Also a doddle to fit, but then I’m a fan of pushfit in general - I guess I’ll change my mind when I have my first leak.

Yeah, I am not sure if they do them without push fit ends, I am sure someone does. However I was connecting onto push fit plastic the only time I used them, which was being a bath changing the tap in situ.

Daniel

[princeperch]

I should have also extended my thanks to the op for inadvertently saving me from a potentially large insurance claim (which in true princeperch style, given I only paid 80 quid for the building policy, would have had a 1.5k excess attached to it)