On Aug 31, 11:36*am, "Bob F" wrote:
ben wrote:
One of the toilets in the house has an intermittent issue with air
bubbles.

Occasionally, when just sitting there unused, a single bubble of air
will 'blurp' as it reaches the water surface in the bowl. *It might
happen once or twice in a day, or as many as ten times (possibly
more). *The toilet has zero problems as far as function go.

I think we first noticed this last year but it went away after a
while. *It returned a couple months ago.

I've read that a clogged waste vent could cause this. *I've looked in
them (from the roof) an don't see any blockage. *The other toilets in
the house don't have this problem either.

ideas?

It sounds like an obvious vent problem. The vents should divert pressure
differences to the outside.

I suppose it could be related to vent fan usage in a well sealed house.- Hide quoted text -

- Show quoted text -

Or, the pressure outside of the house could be greater than the inside
of the house. If you have a newer 'air tight' house, and you use a
kitchen fan for example, to pump air out of the house, then you might
create enough of a pressure difference to suck air in through the
toilet... Just a thought (do you feel wind every time you open the
outside door?)

John