AJB wrote:

Where the water enters the bowl rim, there's some sort of moulded
widget that forces it to shwang off in one direction or the other.

Ours had come off the end of the pipe. I couldn't get it back on without
removing the toilet, but could tell that it was loose by poking my
finger up the back of the loo rim (ugh!) - it wobbled.

I reckon on mine it's moulded into the ceramic itself.

Anyone got recommendations for domestic water softeners?

--
Happy, sad, cross and concentrating.