And I’ve a theory. The first flush is always OK. And it’s only used occasionally in the night so nothing much goes down there. How many times do you go to the loo, flush, and that’s it - walk away. So, you never know any different. It’s only when I came to clean it that I flushed it multiple times and it backed up. So it probably wasn’t the few bits of paper I put down with my vinegar on, I reckon there’s been a blockage there for ages, I’ve just never known. What do you reckon? So, when they come to unblock, it will probably be from months / years ago.