You can see the results of Super STAR Network’s survey on BCDs by going to their website. It showed that 50% of respondents had had a problem with their BCD, 42% rarely and 8% occasionally. The most common problems are stuck inflator valves and accidental button operation / confusion.
28% of people never get their BCDs professionally maintained, and a further 18% only do when a problem happens. I have to admit to being in that 28% who have never had their BC professionally maintained, although I have cleaned up the inflator valve whenever I’ve had trouble with it. I have problems with a stuck inflator valve on a Halcyon Eclipse wing almost every year. Mine is the old metal inflator which Halcyon did seem to have trouble with and don’t use any more. What tends to happen is that it sticks slightly open, but not enough to be obvious. Gradually I find my buoyancy is off and I have to dump some air to maintain it. Eventually it dawns on me that I’m having to dump air while my depth isn’t changing, at which point I realise what’s happening and disconnect it. Then I have to take it apart and clean it up. On a Philippine dive trip soaking the bits overnight in vinegar seemed to do the trick. I really should change it to the newer plastic one, but I quite like the response of the metal one – the plastic one doesn’t feel quite the same somehow.