In the last few days we've had high water level in downstairs toilet. The first few flushes are good and waste flows away but eventually the water level rises in the pan to perhaps half the height of the pan and takes some hours to drain away. Last night I poured 6 large buckets of hot water with washing up liquid into the pan. They all flowed away very fast with lots of gurgling. It seems to be that if the water was poured directly into central lowest part of the pan the hot water just disappears like there is no obstruction. If poured to the side of the pan the water disappears more slowly and seems more likely to cause a high water level, (but this may be madness on my part ). When left overnight it drains away to the normal level. It then takes 6 or 7 flushes before the water level starts to rise to half the height of the pan again. I've tried a sink plunger but its really too small and just pushes air around the u bend. We've ordered a R. SIGA 2 Way Rubber Toilet Plunger, Aluminium Handle and Faithfull Tools FAIPDRWCAUG Deluxe Toilet Auger - Clear off Amazon in the hope these tools may provide a fix. I would welcome any suggestions as to what may be wrong and what has to be done to correct this. Very many thanks to all.