Place 3 pieces of toilet paper in the bowl and flush if the bowl evacuates the toilet paper lower the green dial setting by one number and repeat flush. You will hear the toilet fill valve running occasionally to refill the toilet tank. Best Dual Flush Toilet Top 5 Recommendations Dual Flush Toilet Flush Toilet Within mere days your toilet can leak out water which can fill up an entire pool. Dual flush toilet running . Sometimes you may find that the fill valve always open and filling the tank. If you have a dual flush toilet that is constantly running most likely the dual flush valve seal is worn out warped or dirty and hence not sealing properly. Over time this rubber piece may become brittle or simply misaligned. Dysfunctional flapper is the main cause for dual flushing toilets continuous water running. To check it turn off the water supply and flush the toilet to completely empty it of. Toilet running constantly When the toilet is constantly running we must first find ...