"John Rumm" wrote in message
...
Peter Andrews wrote:

Nearly as good as one I fixed last week. One toilet extract blowing
into
the next toilet, and only one fan installed - nothing to the outside at
all.
All done by a 'professional' building company. Customer had believed
for 14
years that he had two extractors:-)

Did I mention the one where I found an extractor blowing into a cavity
wall (i.e. only through the inner leaf).

I think this shows that most fans are installed to keep the BCO happy, not
to actually be used :-)