This is going to sound really stupid but I am pretty sure the water level in my toilet reponds to changes in air pressure. Can anyone confirm how likely this is?

Surely the air pressure is the same both sides of the water.

[Edited on 21/2/06 by stevec]

Exactly what i thought but it does, appear to rise and fall with air pressure,

Ours goes down when you flush and then comes up again . Seriously though, it does move when there's a strong wind over the top of the soil pipe

that must be it, its responding to the wind, which can be at times pressure related

Boy you are getting bored!

Get out there and build that car !!!!!!!!

My toilet is affected by wind but not that sort!

That would do it though, wind over the soil pipe,thats how the fuel comes up yer main jet on yer bike carbs aint it?

Yep! Venturi effect....

"Yep! Venturi effect.... "


Wouldn't happen to be an old SU toilet, would it?

If it is, have you checked that there's a little oil on the damper sleeve . . . ? It won't work right dry.

I believe in the context of waste disposal porcelein the correct term for this is the jalfrezi effect

Mick