Help with light switch

[6beachlover]

Swapping an old light switch to newer one, well getting partner to, taken old switch off and it has 2 red wires! (Bedroom has 2 lights operated by the same single switch). Included pics of old and new- had 1 red wire in each L1 and 11 on old switch, where would these two red wires go in on the new light switch please? Seems to have more places it can go on the newer version which has L1 and L2 twice. If it’s not straight forward I’ll get Electrician to come.

Well one red wire is the live amd the other L2 is the switched live. These wires are not connected when the switch is off.

I'd think that you just put one red one in L1 and the other in L2. ( On the same side).

Does the new switch have two switches on the front. Not sure why it has 4 terminals otherwise

You have bought the wrong switch. It’s an intermediate switch that is used on circuits with more than one switch controlling a light. Hence why it has 2 L1 and 2 L2 terminals.

However you can still use it. The only damage done is you have paid slightly more than you needed to. Put the L1 wire from the old switch into one of the L1 terminals, and the L2 switch from the old switch into one of the L2 terminals. Then leave the remaining terminals unconnected.

Also don’t forget to connect the earth, but I’m sure you know that.

Mostly in the UK the mains (live, neutral, earth) comes to the ceiling rose, not to the light switch. Then the live wire goes down to the switch, and the switched live comes back up to the light.

So, it's actually a bit unusual that both wires in your light switch are red, as that would mean they have run two cables, with 4 wires, when they only needed one cable with 2 wires. Shame you didn't take a pic with the wires connected.

But, bearing in mind that it's a light switch and only has 2 wires, one must be live and the other the returning switched live. For the switch itself, it doesn't matter - but be careful when working on it, switch off the lighting circuit.

The new switch in your second pic is an intermediate switch (AX) used when there is more than 1 light switch (I think actually more than 2...). You need to get the same as you have, which is 1-gang, 1-way. I see that it's Legrand brand. Looks like this one:
https://www.amazon.co.uk/Legrand-Synergy-7300-00-switch/dp/B00KJDD5T6/ref=sr_1_15?dib=eyJ2IjoiMSJ9.-wIQgMyphqpM7ScpzkO5n42LM19Xw-Mk4cJnA5tf1jra_SxuSL8npp8ct4Y6orY1bsDcqinqAmGy3THDKzxDPNYZJcXYypWf2YRvzgZvKIS8OajrOg_Xi-TrntSALLdCDkdDctJdf7KiD5VkIcTGuz9YyNAwPVQIoJglGqKIl9sWTZzY1yPQXp2KKP-85YMF9Q93gPzZjPN-lD-nBmu36WyP69LLzp00eAulTiaswAw.f_v1q4Lx-WdkUJtgPu9EQZMER4BewUIaIFpDlBjfn6A&dib_tag=se&keywords=legrand+light+switch&qid=1740337337&s=diy&sr=1-15

@filka The OP doesn’t need a
to get another switch. The one she has will work just fine, just with a couple of terminals unused.

Thanks, yea 1 is live as screwdriver glows red on just the 1 wire. Obviously we did shut power down but did test see which wire was live firstly! Thanks. Old house so first time we had taken this switch off to replace to a new model.

Thanks, yea that’s my fault! Didn’t realise when in B&Q. The switch only has 1 switch to operate both lights which is how the old one was just a single so I just picked one that looked the same 🙈

Thanks, so partner said as no earth wire when screw the x2 screws through the front plates to the back box that earths it! Hopefully that’s right!

The earth wires should be fixed to the back box, so you wouldn't have needed to disconnect them to take off the old switch or fix the new. But worth checking that they are there and that the connection is good.