Bathroom lights going off and on again

[BlueJohn]

We have six halogen lights set in to the (plasterboard) ceiling of our bathroom using IP44 rated sockets (the ones for bathrooms).

When the rooms steams up a bit, one or other of the transformers (there's one for each gang) seems to cut out for a bit. At least, it only seems to do so when the room steams up. We have an extractor fan, so it doesn't get that steamy though.

The transformers are pretty meaty by the looks of them though, so I don't think they're overheating. Could it be something else?

[David Hansen]

On Thu, 14 Feb 2008 02:28:16 -0800 (PST) someone who may be BlueJohn wrote this:-

Not very sensible, a triumph of fashion over practicality. Did you install them, or were they installed before you moved in?

If the same thing doesn't happen after the same period of time when the bathroom is not steamy, then that is fairly conclusive. I would suspect that the steam is getting in somewhere and causing a thermal overload protection device to operate on the 12V side.

Have you looked above the ceiling when the room is full of steam? Is it getting through somewhere? How well protected against moisture is the 12V wiring?