: What would cause a toilet to drain over a period of time? When flushed, the bowl refills to the proper level. After about 5 hours the bowl is almost empty.
Rob, You have a problem that seems to happen in my house also.It doesn't drain down as far but it goes down. I am on a septic system. Are you? Syphoning is the only way that water is going to get pulled out of the bowl. A clogged vent can cause this. Also a partically plugged sewer line or full septic tank can do this. Hope this helps. Dale Peck LMP