WC Pan water level

[Hayabusa]

Been looking for an answer to this for awhile and seem unable to find an answer, if anyone can help me it would be much appreciated.

Basically the water level in the pan on my toilet has dropped by maybe an inch since I originally moved into the house some 6 years ago, when you flush the pan will fill up to where the water level used to be, and obviously should be by the pans design, then the water will slowly lower until it is maybe an inch lower than this then stop.

What we are concerned about is there is a leak somewhere or something.

Anyone have any advice please?

 

[noseall]

the water in the pan should be level with the lowest point of the outlet pipe at the back. you can check this by placing a spirit level true across the pan, front to back. use a tape measure to compare.

 

[TicklyT]

Could there be anything trapped in the trap, so to speak, that could be working like a wick. That could slowly draw the water level down.
Time for a mirror on a stick to have a look round the bend?

Is there a vent stack or air admittance valve, and is that clear/working?

Could also be a partial blockage downstream somewhere drawing the trap as the flush flows past it

 

[ChrisR]

Could be porous glaze?

 

[sime10]

Could be a thirsty dog ( not unkown)

 

[sime10]

sounds like a partial blockage. Lift that manhole and have a look