Loss of water in WC pan??

[studiot]

Standard S trap rimflush wc pan, mounted on tiled concrete floor.

The level of the (trap) water in the pan fills to normal after flushing but immediately drops significantly. The system has worked normally for years before this problem.

There is no sign of leakage and the outlet fits into a socket cast into a concrete floor. There is no sign of movement.

Any ideas welcome?

 

[seco services]

slight blockage in waste pipe

 

[powell30]

Spot on.....try to plunge if all else fails, take the toilet off and try to clear down the waste pipe that way

 

[studiot]

Thanks a million for the advice.

The blockage was not in the wc connection but the main house drain.
Luckily your advice alerted me before the situation became too serious.

I owe someone a pint.