Toilet flush - suddenly loud in pipes

[LottieCrackerton]

Our toilet flush has suddenly started making a loud, sort of hollow noise in the wall pipes in the bathroom. What could be the reason?

Water hammer probably, call a plumber

Turn off water under sink.

Turn taps on in house...
Flush Loos
Turn tap under sink back on and turn taps off...
This is all a plumber will do, as it is an air lock.

Ah, glad I spotted this, helpful as this is happening to us too. Loud and proud it bangs and clangs away sometimes, then silent some other times, just to fool you.

Airlock you say? I'll give it a try thanks mummy2017

Sorry you do need to turn the taps off.. before you turn the tap under the sink back on...always mix that bit up.

Please open the cistern lid and take some photos of what's inside.

Flush it while you have the lid open to see how it works.

Does the noise occur during flushing or during refill?

An airlock is unlikely.

It's after the flush Piglet John.

any chance of photos?

Can I say a huge thanks to @mummmy2017 We’ve had a banging noise for months after flushing the loo. Really very annoying, have just carried out the steps you suggested and voila - problem solved!

Water hammer perhaps.

Replacing the ballcock and flush (about a tenner from b&q) will probably fix it. Technically it's probably just a seal/ washer that's the problem but it's easier just to replace the whole part.

Yep. Ours did this. Had a plumber round looking at a much bigger job so whilst he was there I got him to take a look. He just quickly swapped a washer. The noise had been awful. Was a bit embarrassed that all it was was a washer. He just laughed and got on with quoting for the bigger job. Which he got, obvs.