Hi,

After reading this newsgroup and the very clear Readers Digest book
on plumbing, I braved replacing the flap valve in my sister's toilet.
I took the job steadily and got the cistern off the wall - thank
goodness when it was installed a ball-o-fix valve was installed on the
supply side. The metal plate underneath the cistern was rusted, the
foam seal was crushed and the flap valve was shredded (how that
happened I don't know). How the toilet flushed at all is beyond me.
Anyway, I bought a new siphon from the local plumbers' merchant -
which seemed incredinbly wasteful since it was only a thin film of
plastic (the flap valve ) that had failed - but I was pressed for time
- and the replacement is accessible by unscrewing the top should there
be problems in future. Having to take the cistern off the wall to
replace a torn flap valve seems crummy design in the extreme to me. I
also got all new coupling set. Parts came to £15 - plus two hours head
scratching and cursing. The original assembly was all "upside-down" so
I had to rethink how it fitted together - when I twigged the
arrangement it was plain sailing.

Goodness knows how I would have tackled it if there wasn't that
isolating valve on the supply to the cistern. When my house is
replumbed it will be accessible valves all over the place. If the flap
valve fails in future, I'll make my own replacement.

Now my sister has a flushing toilet and much easier access to the
siphon should it fail in future.

Clive