Plumbing in the Home/plumbing


We have a toilet stool that seems to leak water from the bowl.  Never is any on the floor, but after flushing, the water level slowly drops.  It never loses all of the water, but enough to make it interesting>  Wonder why that happens Thanks , Richard

Hello Richard,
All toilets have a "trap" cast into the bowl similar to the one you see underneath your sink. If there is a problem with venting, the trap can act as a siphon once water starts going down. The water will continue to move through the trap until the water level gets below the upper edge which allows air to enter the system and break the siphon.

So… This sounds like a possible venting problem. Think of what happens when you put a drinking straw into a liquid and then remove it while keeping your finger over the top end. The water will not drain out of the straw because a vacuum is created in the system by the weight of the water. As soon as you introduce air into the system by removing your finger, but water can then drain out. A plumbing system operates on the same principle by using piping that goes up through your roof to introduce air into the system and break any vacuum. If this event is blocked, the draining water will create a vacuum and continue to pull water out of traps until they get low enough to let air in.

The solution is to clear the blockage in the vent line. This blockage can be caused by several things including snow if you live in an area where there is snow. The snow can block up the top opening and cause it to freeze over and close up due to contact with the moist air coming out of the vent pipe. This usually only happens on smaller diameter vent lines.

Getting the actual sewer lines and possibly the vent lines cleared out with a snake often resolves this problem.

Good Luck,

Plumbing in the Home

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Dana Bostick


Pretty much any residential plumbing questions. For "item specific" details such as a specific model of fixture, I will need to research and there may not be any useful information available. Note: I live and work in Southern California. We do not, as a rule, use hot water or steam heating systems, oil fired boilers or private water wells so my knowledge in those areas is pretty limited. There are others here on AllExerts that can probably answer those questions better.


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