In article ,
Rednadnerb writes:
Hi all
After working OK since it was installed a couple of months ago the RCD
started tripping whenever anything was switched on.
After failing to isolate the problem by disconnecting circuits we (the
installer and I) realised that the RCD test button doesn't work, so
after a quick dash to Screwfix we got an identical one and installed
it but it's exactly the same! pressing the yellow test button does
nothing. Could it be we have two faulty RCD's or is there something
we're obviously missing?

Does the RCD have an earth connection? (Most don't, but a few do.)
If it does, I might guess the earth connection is faulty.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]