WC - U Bend

[Rod Serling]

My toilet pan has barely any water in the u-bend. i know this is to do with the cistern draining into it. It fills after a flush, then drains to almost empty aftyer 10 minutes or so, but not quite empty. I don't think there's any leaks, is it pipe, cistern or another problem?

[buildersmate]

This more normally occurs because movement of water in the drains on the sewer side of your toilet pan is syphoning the water from the U-bend and into the sewer side (put technically, the air pressure on the sewer side is being lowered so the U-bend water is being pushed out into the sewer). If it is this the case, the 'closed' soil system needs to be vented. This means there should be a soil stack which is open to the air at a high level (above the eaves level).

[Rod Serling]

Thank you, buildersmate, i'll give that a go, or call a plumber!

[SpamBammer]

sounds like a big turd stuck somewhere

[Malagabob333]

Or it could be an object lodged arond the bend allowing the water to siphon away