Hello!
My boiler's switch, everytime I close it, is flashing blue electrical light, but not always. I didn't think I have a problem till the second time I had to replace my switch, since it'd stopped from working.
Anoter fact is when I replaced the switch I saw that one of the wires (If I remember correctly it was the brown wire) got black but just a bit, so I guess it was from those reccurent blue electrical lights.
Can someone please tell me what should I do for replacing the switch for the last time?

Thanks to all who answers...Beer 4U2

 

Welcome to the forum.

From the way it sounds from the discoloration it sounds like the wire may have been loose on the screw and caused an arc when the switch was operated. Loose connections cause heat, heat discolors insulation.

Was the switch rated heavy enough for the load it was operating?

 

Is this blue light really a light or are you seeing and arc/spark?

 

All switches spark when turned on and off. All of them. Some a bit more and some a bit less, but they all spark if you look closely enough in a dark room. The higher the current, the more slowly you move the switch, and the lower quality the switch, the more it will spark. The darker the room and the more closely you look, the more likely you are to notice it.

If this spark is unusually large or bright, you might have a problem.

 

"Was the switch rated heavy enough for the load it was operating?"
Answer: The switch I bought is especially made for boiler.

"From the way it sounds from the discoloration it sounds like the wire may have been loose on the screw and caused an arc when the switch was operated"
Answer:well, I think I closed the screwes pretty tight, but I'll notice it this time.

"Is this blue light really a light or are you seeing and arc/spark?"
Answer: It's more like a spark which may be normal but since it happened again an again this might be the reason why it's stopped from working.

Really appreciate your answers, thank you.

 

How old is the boiler? The switch may have been designed for the boiler when it was new, but as some devices age they lose efficiency and draw more current -- especially at startup. Not saying this is definitely the problem in your case, but it could explain the multiple blown switches.