On Wednesday, March 28, 2018 at 8:16:30 AM UTC+1, Rednadnerb wrote:
I had the same thing happen on a bath hot water feed after 4 years use. 1st floor flat, made a mess.
I now replace them at the first signs of discoloration and get them from Wickes because their website says they are WRAS approved (although this is not stamped on the product or printed on the packaging - so I have my doubts) rather than from Screwfix because they are not WRAS approved.

Even the named brands that are WRAS approved are similar in price to SF etc..

I wonder about John Rumm's comment re twisting and kinking. As this was a d-i-y job, always tricky under a sink, that could have been a factor. Well, now it's a g-s-i job as hands and knees working is out for me.