On 01/16/2016 5:41 PM, DerbyDad03 wrote:
....

That said, I have to assume that some of you have a guest shower that
goes 20 days without being used. Are your traps empty after 3 weeks?

It does seem a little short but much would have to do with the actual
conditions in the house as far as evaporation rate and what the actual
trap design is; they're various shapes and mayhaps this one is "more
flatter" than others. It's also possible there's some suction being
applied owing to venting but my bet would it's not the issue and might
as well eliminate the quickie, easy as the culprit first.

As for the question; not here, no, we don't in specfic. There was one
in the basement in the house in VA but it was a floor drain with full 2"
drain so the size of the trap was quite large compared to a fixture
drain so no comparison.

I'd still posit as my best guess it'd behaved the same way while the
house was occupied if the shower (and probably a shared lavatory?) were
_never_ touched but that it didn't occur owing to there being the
occasional use or even just routine cleaning, etc., that would freshen
the trap without your even thinking of it or recalling that such did
happen now as it was so routine.

But, yes it is possible there's a new phenomenon altho I'd really be
hard pressed to think of something outside the house; there being a
blocked vent from a bird nesting or somesuch would be higher on my list
than that (see above)...

Good luck...

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