Toilet won’t flush

A toilet that will not flush properly may have an issue at the cistern, the pan or in the soil pipe downstream. If the cistern fails to discharge a full volume of water, the cause is usually a worn flush valve, a misadjusted siphon or float, or a partially closed isolation valve. If the cistern empties correctly but the pan does not clear, the obstruction lies in the trap or branch pipe and typically involves wet wipes, excessive paper or foreign objects. Building Regulations Part H1 and BS 6700 set out installation requirements intended to maintain reliable flush performance. Engineers usually address common causes by inspecting the flush mechanism, the rim jets and the connection to the soil pipe. A CCTV survey is recommended if multiple toilets are affected, as the issue may be in the main drain.