The sink in my bedroom had been draining slowly for a couple of weeks. Then last week it stopped all together. Tried everything. Long story short, it was the pipe on the outside of the house that had frozen solid. So after establishing it wasn’t a blockage in the 5 or so feet of pipe that I can get to in my room, I put it all back together. It drains away pretty much fine now. Except once the water drops to a certain level in the U-bend, it starts sounding like it is dripping inside the U-bend. There is a very minor leak from where the pipe screws to the sink (this is not the source of the dripping sounds). Could it be to do with this? Shinning a torch down the plug, I can see the small amount of water at the bottom of the U-bend moving every time it ‘drips’.
Any help much appreciated.