S
Shutpa
Have a cistern with a double flush button. Tonight after flushing the toilet, nothing happened ie there was no 'filling up'. Thinking that there may have been a stoppage on the cold water supply, I turned on the tap at the nearby sink. Immediately, the cistern began to fill up. Later my wife called me to say that the cistern wasn't filling up, so I turned on the tap again and once more the cistern began to fill up. I imagine that it may be an airlock of some kind but that's only a guess. What do the experts think