When i flush the toilet at home, it flushes fine but the water level after the flush is very low (almost to the bottom of the toilet). Does this mean its blocked? I always assumed if the toilet was blocked the water level would rise.
If your bog was blocked then your water level would be higher after a flush and would possibly slowly return to the correct level over time- depending on how bad a blockage.
A loo works using an S bend- basically the amount of water left in the loo after a flush has got to be level with the bottom of the outlet pie- simple physics. So where is it going? Have you checked around the back of the loo? If there is a crack or the outlet pipe has shifted then your floor may be soaking.
Its probably partially blocked. What then happens is that the water passing through the partially blocked bit, which could be several feet from the loo, is creating a partial vacuum in the pipe which is 'pulling' more of the water out of the water trap than its supposed to (down the soil drain), leaving the level lower.