Have noticed over past couple of days that when the toilet is flushed, a short while after a loud chugging noise is heard and the toliet shakes slightly. Any ideas what the problem could be? How to fix it?
An easy way to check for the answer to rosebery's question is to turn off your mains water then flush the toilet. If the noise doesn't occur it suggests the filling system. If noise still present then it's likely to be the waste.