Pelect

You need a neutral wire from the light. If you are not familiar it is best to engage an electrician to pull the additional wire and wire up the light switch for you. Not safe to DIY if you are not familiar.

Finger jointed Meranti (1X2) is one of the cheapest but X4 is not going to be cheap. It's going to be difficult to find straight wood more than 1.2m without finger joints here unless you want to pay much more. Let us know where and how much if you managed to find what you want. Pine is expansive here and not commonly available.

First ensure the 3 sets of lights are all on the same circuit. Verify this by turning on and off the breaker for that circuit. Once verified, all you need is a signal neutral wire from the same circuit. No need to connect 3 neutral wires. Best to engage electrician if you are not sure.

It's against the wiring code and you are right the wires from light switch are not of the correct size for power sockets. Besides, most light switches do not have neutral and earth wires at the switch itself.

Good you are curious. Let's use method 3 for the purpose of this discussion. As I mentioned earlier, you need a neutral wire for the switch to work (fully working). The touch switch, just like the touch screen of a mobile phone, requires a tiny amount of power so that as soon as you touch, it will sense and turn on the switch. So how come in method 3, although 'neutral' is not connected, yet switches 2,3 and 4 can still work and why do they switch off as soon as switch 1 is touched? (remember, your blue neutral is actually not a neutral. The blue wire is connected to something else. You should be able to tell what is being connected to the blue wire because the equipment connected to blue wire will not work if you leave it unconnected just to see what it connects to) Where did the switch gets it 'neutral' from? Well, it gets it indirectly via wire 1 which is connected to your light/lamp which is connected to the neutral. if your house is wired correctly and there is no sharing of neutral, then you can try to remove ALL the lights from switch 1 and see if switches 2,3 and 4 will still turn on. When all switches are off, the live wire is at 240V. When switches 2,3,4 are closed, they are also at 240V. However, when you close switch 1, it will also be at 240V. When switch 1 is at 240V, it will be the same electric potential as the live wire. Now switch 1 is no longer at 'neutral' and therefore the entire switch no longer works and lights 2,3,4 will also turn off.

From a safety standpoint, it is not worth the risk to attempt to take on this task. So, please get an electrician. However, from a knowledge point of view, it is good to know what's going on. First, the new switch will not work without the neutral. The touch switch requires power to operate and that is supplied by the live and neutral. Also, you can see in the wiring diagram the neutral to the new switch comes from the same lighting circuit. So, when your electrician comes to install, you should see where he gets the neutral to the new switch from. It is not just any neutral, it should be from the same light circuit. Any other neutral might work but it is not the correct way to wire and it could be dangerous. One word of caution, after you have your electrician pull the neutral wire into the new switch, do not under any circumstances attempt to switch wires around, you could get a nasty short circuit between live and neutral. Things will become clearer after you see your electrician wired everything up.

The blue wire shown is not a neutral wire. If it is, it would be a direct short circuit. Most homes do not have a neutral wire going to light switches. It is dangerous to be swap wires so as far as possible, do not attempt to swap wires without first determining the origin of the wire. Also, the neutral wire, if you manage to pull one in, has to be from the same circuit as the light.

One aspect commonly overlooked is with regard to spare parts and after sales service, if the heater is not too difficult to access. You can call the main dealer to find out if they stock spares and whether they also provide repair services.

Screw type E27 also got horizontal type for low ceiling.

Usually the downlights come with PLC push fitting. You tell the shop you want to change to E27 screw fitting and they will sell you the additional E27 screw fitting holder so that you can swap the holder. If you cannot find, go to Choo Chiang. Google for address.

Do you mean you want to remove the 20A cover to expose the screws? If so, just tilt and pull it out. Could I ask how do you know the switch is not working? P.S. Don't forget to switch off the circuit breakers when doing electrical work.

So, what is the electrical fault?

I was referring to the diagram on the inside cover of the upper box. Could you take a clear picture of that. The pictures posted are blurry. The diagram you posted shows you have home automation, but I noted that the upper box has been unplugged. Is there a reason why it is unplugged. Your home security is no longer in use or is there some other issue? When you say heater circuit board switch, are you referring the the switches on the lower box; i.e P12 and P13? Since you say that there is electrical power trip related to heater, it is best you do not turn on P12 and P13 until the root cause has been found. They should be left in the off position and the heater should not be used at this point in time. In my opinion, it is best not to over complicate things and first determine whether the heater is really working without electrical fault or find out the root cause of the power trip.

but something is tripping the power. so still cannot conclude it is working well. The failure of heaters may not be sudden. Initially, there may be random trips at long intervals. These intervals get shorter and then after the heater is turned on for say 5-20 minutes, it will trip the power. And finally, the minute the heater is on, it will trip the power. In some cases, the failure is instantaneous. The minute you turn it on, it will trip. So, it depends on the symptoms. Power tripping when heater is on is usually due to heating element, not always but very often. There are various ways to verify this and unless some tests are done, it cannot be concluded whether it is a heater issue, wiring issue or some other issue. As for heater switch, there are many options and brands available in the market. It may not be exactly the same as what you have but it should work. If you post the wiring diagram, it may help shed some light. By the way, if you re-wire the whole house and the heater is still not working, you still need to buy a new heater. If it is a heater issue, you will save thousands of dollars re-wiring the house. The LED light coming on by itself has been discussed in this forum and many other forums. The common issues are incompatible dimmer switch, switches with light indicators and very close wires due to 2 way switches or placement.

Personally, I would never bypass something without understanding what are its functions. A storage heater has several safety features, protecting against over temperature, a tank with no water coming in, excessive pressure and safety cutouts. Personally, I would put safety above all else. What is the brand of this heater and are you able to contact the manufacturer or dealer? By the way, please do not touch anything inside the upper box. It seems there are many live wires inside on the left half. I would be very interested to see a clear wiring diagram on the inside cover of the top box. I am really curious what this is.