Many thanks, ericmark. However, although I can see what you mean on the photo, it doesn't in fact have a circlip. I've tried turning the fitting but it won't budge, though I've not tried too hard in case I break it.
The GU5.3 lamp has just to pins and can fall out unless held by a clip of some type normally a screwdriver under the loop of the clip can prise it out. Once the clip is removed the lamp needs pulling out and often that is not easy.
The whole lamp is normally held in the ceiling using spring loaded clips and to remove you have to pull down from the ceiling wangling it to try to force the clips up without too much damage to the ceiling. Normally there is some little damage that can't be avoided.
Once out you can get fingers behind the lamp to push it out of holder once circlip is removed. Today these are being replaced with low voltage as the extra low voltage (12v) need an electronic transformer which stops one using LED replacement lamps and often fails with the lamp. Once a low voltage fitting is used GU10 then removing lamp is far easier you have a rubber sucker and you simply twist lamp and release the bayonet fitting.
The problem is where the transformer can't be accessed through the lamp hole. I theroy the transformer should come through the hole where lamp was but in practice often fitted while floor boards are removed.
The GU10 or GU5.3 refers to the electrical connection. And MR16 or MR10 refers to size of reflector. Neither refers to voltage however many shops seem to display the extra low voltage 12 volt lamps as being MR16 and the low voltage 230 volt lamps at GU10 but be aware on the internet you can get all sorts including 12 volt GU10 and 230 volt MR16 well in fact a GU10 is often a MR16 reflector.
As it is a bathroom fitting and hopefully designed and purchased with that in mind? They would not come with a fixing clip for the lamp/bulb. The bezel of the fitting would normally be removed by quarter anticlockwise twist. Then you should have access to the lamp. But that could only be part of your problem, if the lamp is a 12V lamp, it may well be the transformer that has gone, rather than the lamp. And that should be accessible via the fitting hole.
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