can you swap all halogen spots (GU4) by LEDs?

Chickereeeee

GU10 and GU4 are the connector type on the lamp. The size (diameter) of the GU4 12v lamp you have is (probably) MR11, which is 35mm. At 240v, lamps with a GU10 connector are 50mm diameter. This make it clearer:

https://www.12vmonster.com/blogs/product-questions/17820529-what-is-the-difference-between-all-these-spot-lights-and-flood-lamps-codes-gu4-gu53-gu10-mr11-mr16-par20

Now, I have successfully swapped 12v MR11 halogen lamps with 12v led replacements, and they worked fine. The transformers are probably 10 years old. ( I have not manged to get dimmer switches to work on 12v MR11 replacements though...).  

I think you have three choices: 1) swap the transformers for led compatible ones 2) fit 240V 35mm fittings with integral led lamps or 3) make bigger holes, and fit 240V GU10 fittings and lamps.

skycatcher

fenwick458 said:

GU4 is just the connection, it can be fitted on both sizes of bulb, MR16 (50mm)or MR11(35mm)
most light fittings for both sizes of bulb are the same size overall so you might be able to change the fittings without enlarging the holes. what size holes (and bulbs) do you have now?
they do also make MR11 bulbs with a GU10 base but for the extra price you pay for them and the fact they are extremely rare it's probably a better option to try and change to the most commonly used ones

Unfortunately they are the 35mm dia ones!

fenwick458

well fitting GU10 bulb holders (and removing the transformer) then using MR11 GU10 would be one solution, easy swap you just have 2 wires to change. 
but you have to question whether or not it's sensible, you're basically going from one obscure bulb to another. the thing I like about a common GU10 fitting is you can get decent LED bulbs almost anywhere for about £1 now.
what type of ceiling is it and how big are the holes in the ceiling?

ispookie666

Please be mindful of the electrical zones in a bathroom which can limit the type of bulb fixtures, voltages and IP rating.  

Older style transformers require a base load to function properly and often the LEDs draw less power than the base load resulting in flickering.  Swapping the transformer out to an LED variant is an option.  But please follow the regulations.  

It is technically possible to void your home insurance if the wiring does not confirm to the required standard.  

skycatcher

Just an update......i decided to go down the replacement transformer route which i fitted today and no more blinking lights! 

Thanks for all your advice!