Ideally yes you should turn off certain appliances at the socket when not in use. If the wall socket doesn’t have an on off switch it would need to be unplugged instead.
Electricity still runs inside an appliance even if it’s switched off. If electricity is present, there is always the possibility of something overheating or shorting out. However, it is far more likely that if something was to go wrong it would be whilst the appliance is in use.
Where does electricity run inside an appliance?
With an appliance plugged into the wall socket electricity runs first through its plug and mains cable. After that it enters the appliance and goes through a mains filter (suppressor). Then on to the on off switch. Theoretically it should stop there until the on – off switch is activated. But it is possible for power to also go to the main PCB, the door lock, control panel.
In the past I’ve known mains suppressors on some washing machines short out and explode (like a firework – but no fire). The washing machines were not in use at the time. To be fair that was a long time ago and on a specific brand of washing machine. But this shows the possibility of something shorting out with the appliance not running.
Recent examples of fires with appliances not running
This article was inspired after reading a recent media article where a tumble dryer had apparently, “caught fire” whilst left plugged in. From the pictures that I could see though it appeared that the fire incident was small, and confined to the wall socket and plug. Someone also added a comment to one of my articles saying that their tumble dryer caught fire whilst left plugged in but not running.
This is what I do
My own washing machine and tumble dryer are in our garage. They are very much out of sight. We always try to remember to turn both of them off at the socket when we have finished using them. Fortunately, this is pretty easy as both sockets are easily accessible just above the appliances..
Our dishwasher on the other hand is a built-in appliance in our kitchen. The socket for the dishwasher is located behind a load of pots and pans in the bottom of a cupboard and behind a back panel. It is accessible, but only with a fair amount of effort. Therefore unfortunately we never turn it off at the socket.
If we ever did have a fire we would no doubt seriously regret that. But as you can imagine it is a lot of extra messing about with an appliance that is used virtually every day. We all have to make these kind of judgement calls. The risk is not great, but is undeniably there.
So if it is easy to turn off the appliance at the wall socket then why would you not? If it is quite difficult then it is understandable that you don’t. But is it possible to rearrange things to make the wall socket more accessible? With my own dishwasher I could, with a fair bit of effort, rearrange everything so that the microwave is plugged into this socket and the dishwasher into a separate one above the worktop. This, is something I need to do.