First let me make it clear I am talking about very mild “tingles” and not proper electric shocks. If anyone receives an electric shock, the appliance should be disconnected immediately and an appliance engineer called out. Mild electric shocks or tingles might not be taken seriously, but they can turn into lethal full mains voltage shocks at any time.
So never use any appliance even if you only get a mild shock from. Disconnect it immediately. The reason you get shocks from a washing machine, or any other appliance, is because it is not earthed properly.
Why Does an unearthed appliance cause shocks?
All large appliances need to be connected to earth for safety. The earth wire runs down the mains cable and then through the socket it is plugged into. If this connection becomes broken at any point in the machine, cable, plug or wall socket, then you can get the symptom of mild electric shocks.
The shocks are often mild, or just tingles because they are caused by small amounts of electricity leaking or inducing across to the disconnected earth wire and running through the casing. It's a phenomenon related to eddy current, but it's not necessary to understand the scientific reason. The effect is useful to us though because without it we would be unaware the earth is not connected unless conditions later allow a full electric shock, which could be fatal.
Such an appliance poses a serious danger. Because the mild shocks indicate that the washing machine is not earthed it means that if a component inside the machine's insulation breaks down, or a live wire comes adrift and touches the metal parts inside, then the low voltage current will be replaced by the full mains voltage – which can kill. Without a path to earth, the washing machine cannot blow the fuse, and instead could just work as normal but be lethal.
Plug not earthed?
The first thing an engineer is likely to check is the appliances plug. They would check inside the plug to make sure the green and yellow earth wire is connected securely.
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If it’s OK, then either the earth wire inside the mains cable could have a break somewhere inside and needs replacing, or it may not be connected inside the washing machine. (The latter is very unlikely, I’ve never known it, but it’s theoretically possible). Both can (and should) be checked with a continuity test meter by checking the continuity between the earth pin on the plug and the metal door hinge or another suitable bare metal point on the washing machine.
Moulded plugs
Most appliances have long since come with pre-fitted moulded plugs which can’t be checked. So if unable to check inside the plug the first thing an engineer would check is the continuity down from the earth pin as described above. If he had a good reading he shouldn’t need to look inside the plug anyway. If the reading was open circuit or high resistance, but the earth was connected properly inside the machine he’d cut off the plug about an inch down and replace it because earth wires can break at that point. If that failed to make a difference he’d replace the mains cable.
Extension cables
If the appliance is plugged into an extension cable then clearly there could be a problem anywhere on the extension. So an engineer would check the earth connections and continuity on the extension cable. Ideally ditch the extensions, they aren’t ideal on large white goods appliances. If one is necessary try another extension (but make sure it’s appropriate – appliances and extension cables). I have seen appliances plugged into totally inappropriate extension cables that are using 2 core cable with no earth!
Wall socket not earthed
Another possibility is a fault in the wall socket. The earth wire could be disconnected inside or the brass earth prongs inside could be worn or too far apart to grip the earth pin on the plug properly. Obviously you don’t mess with wall sockets. If you suspect a faulty wall socket get an electrician – not an appliance engineer.
Don’t confuse with static electricity discharges
If you get just a single short shock when you touch an appliance (possibly accompanied by a cracking sound) which doesn’t reoccur when you touch the appliance again this could be static electricity discharging from your body and is very different to this issue.
John Maidstone says
Spoken with manufacturer today and they said it might be some problems with my socket and not with their hood.
Also one more thing. When i start the hood everything works ok, but i can hear a whisle sound coming out from there also, not just a motor spinning. Is that ok? Seems really strange
Andy Trigg (Whitegoodshelp) says
Hello John. Yes the only way you can get a shock is if the earth is not connected somewhere on the appliance or the electricity supply it’s connected to. If it was, the fuse should trip. Be sure to fix it asap as if there is no earth you get the small electric shock as described in my article, but if a proper electrical fault developed that would change to lethal mains voltage.
Andy Trigg (Whitegoodshelp) says
I would say it’s very unlikely that the earth fault is with a new appliance, and much more likely to be an installation or electricity supply issue. I don’t know about the whistling sound though. I don’t really deal with cooker hoods.
John Maidstone says
Thank you Andy. I will have some picture done tonight and will show you, you might find if that’s ok or not.
John Maidstone says
Thank you for your help Andy. The socket installed was installed without an actual earth wire, so basically just two wires was there. That’s why the applience was giving shocks. Sorted out fantastic now by myself. Thank You
mr battery says
Moulded plug on my washing machine had no earth, so had tingling feeling on finger from sink and water.
very dangerous.!!!!!!
most machines are made in china and have very thin low quality wiring that fracture in the lead itself.
i see this alot on heaters, kettles etc.
Monica McKinnell says
Hi. How do I actually use a multi meter to test a dishwasher that is giving an electric shock when touching the metal door. I have a basic meter. What settings do I put it on & where do I place the prongs?
Andy Trigg (Whitegoodshelp) says
Hello Monica. You need to test continuity between the metal part of the door (usually the hinge) and the earth pin on the plug. Set it to continuity testing so that when you touch the two connectors together the meter moves all the way over to the other side. Then touch one connector to the metal hinge on the door and the other to the earth pin on the plug. The meter’s needle should do exactly the same. This shows there is continuity between the two places and the earth should be OK. If this is the case the suspicion moves to a lack of earth in the wall socket.
Try a totally different wall socket, make sure the washing machine isn’t connected to an extension cable. If it is the extension cable could be at fault instead of the wall socket.
Sarah says
Hi I just put the washing into the drum and felt a tingling like static electric. Felt like pins and needles. The same happened when I put the tab in. I wasn’t actually touching the drum but obviously the washing was. Any ideas? Thanks
Andy Trigg (Whitegoodshelp) says
Hello Sarah. Yes, please read the article. There’s nothing I can say in a comment here that I haven’t already said in the article. But stop using the washing machine because it could turn very dangerous. All the answers are in the article above.