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1victorianfarmhouse 02-19-2013 09:41 AM

Toilet Bowl Water Level Drops on Windy Day?
I know, it sounds odd. But I've noticed that the water level drops about half an inch in the bowl of my main level toilet on windy days. I can see the water moving back and forth slightly, though there is no airflow over it. The level in the tank stays normal.

The upstairs toilet doesn't have this issue.

I am on a well, and the old septic tank was replaced a year ago with a septic holding tank that gets pumped to a remote treatment facility in the village. I don't see how this would make a difference, though.

Any ideas why the water level drops in the bowl?


BigN8 02-19-2013 10:42 AM

How many vent stacks do you have coming out of your roof?

The reason I ask is I would bet there are two on different sides of the roof. The downstairs toilet is on one and the upstairs is on another. When the wind is strong it will pass over the end of the vent stack and create a low pressure area that will draw some of the water out of the toilet being that a toilet does not have a trap behind it. This would also be why the water seems to slosh back and forth a little.

My parents house was on a lake and the wind would get so strong at times that it would suck the water out of the bowl like this. Never was a big deal and didn't ever chase an issue.

CallMeVilla 02-19-2013 10:47 AM

HAHAHA that is a fun one. N8 is right ... wind blowing over the vent stack pulls the water down a bit (actually, it probably goes UP the vent stack a bit). No big deal but it is fun to talk about with friends and family. :D

kok328 02-19-2013 03:29 PM

Same thing happens on my home. Probably happens to alot more homes that we realize.

1victorianfarmhouse 02-19-2013 08:57 PM

BigN8 is spot on. There are two vent stacks on the roof. The one for the lower toilet is on the northwest side, and gets the full blast of wind coming in from the fields. The other one is on the southwest side, which is not only lower, but is also sheltered by the back of the house and the peak of the roof, and by a mature Spruce tree that breaks the force of the wind.

I think the NW one also doesn't have a great baffling on it, something to work on when the weather gets warmer.




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