more common that the drain is blocked
but wc outlets are still prone to blocking
we use an auger clears them straight away.
hi-spec plumbing & heating (essex)
July 2009
I get this on a semi-regular basis - with my system it's never the bend that's blocked but always the outlet pipe in the inspection chamber outside - if you have one, lift the lid and take a peek - then you'll know.
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