I came home after a few days of being away and there was no water in my toilet bowl. I flushed and it filled up, but the next morning it was empty again? I have no idea whats wrong but have noticed in the past that the water level was slightly lower than you would expect.
Difficult never came across this before. It could be a cracked bend and it's leaking out but I would have thought that would show up. Syphoning action more logical If all wastes go into the stackpipe [Large waste pipe serving the wc then one of them could be causing syphoning if the airadmittance valve is not opening you could then see a local plumbing shop and ask their advice on how to replace the valve or what ever makes it work..
bob
August 2005
This can also be caused by a minor blockage. If a piece of toilet tissue or similar is trapped in the U-bend, it can lie in the water and syphon the water out over night.
Paul Higgins
July 2005
Either the bowl is cracked and leaking or there is a blocked air admitance valve which vents your drains
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix toilets.