Faulty Light Switch?

[Soph01]

Hi,

Three times now I have turned a wall switch off and as I do so there is a flash of white light in the socket almost directly behind the actual switch. It is connected to a heating system. Is this something I should get checked out? It only happens when I turn the switch off. It is just a standard switch, like a light switch.

Many thanks

[SeaJayPea]

Are you saying it switches a heating system on and off? If that's the case, I'd get it checked out as soon as possible. Might not use it until it's been checked out.

[Soph01]

yes, it turns the hot water on and off. Could it be a fire hazard?

[RATTER15]

I think that is quite normal to be honest, I think your are just seeing the circuit being broken, truth be known all switches flash a little if you look closely when in the dark.

[SeaJayPea]

If the body of the switch isn't getting hot, then probably not. But I'd still get it checked out.

There are others on here far better qualified than I who will be able to give you a better answer. I'm just saying what I'd do.

[Prudie]

Lots of mine do, I get a bright blue flash every time I switch off my hairdryer for example.

[Soph01]

thank you, really appreciate your advise

[Iggle Piggle]

It's not good to get a spark behind the switch, it could mean the contacts maybe wearing out or dirty. Not good in any switch. Get it changed.
If the contacts are pitted or worn, heat might build up and destroy the switch contacts or worse, become a fire hazard.

[woodchopper]

When you break a circuit under load - the instant the circuit breaks it causes a gap in the contacts causing a greater current load for a micro second causing the blue/white flash you see. Some makes of switches are better not for seeing this flash such as MK, but all do.

[Old_Geezer]

Not a light switch then. Well it may or may not be the case that heating circuits spark across the gap when disconnected. But it doesn't happen to me, and if it did I'd replace it assuming it was breaking down. I don't believe I should be putting my fingers on a switch that sparks.

[SeaJayPea]

I've just checked with an electrician and he's saying that if this is an ordinary light switch it should not be used to switch an immersion heater on and off. What should be being used is a fused switch. Might be an idea to get it sorted.

[The Builder]

I doubt if it's an ordinary light switch. For an immersion heater, it could be a 20Amp double pole switch that actually does "look" like a light switch.

A regular 10A light switch would have burnt out long ago. It doesn't have to be a fused spur though. Especially if it's a "dedicated" immersion circuit.

Easy to change it for a better quality one. One that doesn't arc at the poles.