things that could cause an unattended washing machine to catch fire

[andyr12345]

I read one of your answers to a post Andy about not having a washing machine on overnight or left unattended if you go out and it got me thinking what components of a washing machine can cause fires especially with a lot of washing machines these days with a 24hr timer built into the front facia  for that very reason to avail of putting on the washing machine overnight to avail of cheap rate electricity and have the clothes finished washing by the time you wake up. In fact our new Samsung washer has wi-fi where you can start and stop a wash when you are out of the house as one of its features ... so actively could encourage people to start a wash whilst out of the house , for convenience rather than anything else.  

here are the things I can think of , can you think of more? 

1.) You have a washing machine on and the motor stops turning (maybe drum stuck or drum bearings have broken and cannot turn or the motor spindle itself stops turning / seized up) then the brushes (if its an older / cheaper carbon brush type motor) are stuck on the armature and then overhead and either burn out the carbon brushes or the armature where the brushes sit on or overheat the coil windings in the motor - sure there would be a lot of electrical smoke and smell terrible but there is nothing really flammable is there around the motor? ... oh hold on I forgot about the plastic outer tub above the  motor , yes the motor on fire could set the flammable plastic outer drums I suppose. But IRL would not the motor be seized and very shortly afterwards would be sending so much amperage from the motor electronics board full of components wouldnt a capacitor or resistor or a chip or regulator or transistor or even a fuse on the motor board short out before the motor had a chance to overheat and catch fire?.
Plus a lot of newer washing machines in the last 5 years or so are now fitted with induction brushless type motors where they dont have brushes sitting on the armature like that - would they catch fire if the power was still going to the motor and it was seized and could not turn would that still overheat the coil windings catch fire ... I dont know maybe it will, have not tried it. I know on older washing machines with carbon brushes the carbon brushes really do spark an awful lot, especially when machine goes into spin or has some heavily worn carbon brushes in them - I suppose the sparks could (million to one chance?) catch alight to some kind of sound proofing material/felt on the insides of the washing machine casing  if manufacturers have included sound proofing inside the machine which most dont I dont think.

2.) Ok so that's the motor covered. what's the next thing I can think of ... er the heater element at the bottom of the drum - i suppose there is a risk that could catch fire , but it goes through a thermal cut out and should be OK as long at the heater element at the bottom of the drum is submerged in water at all times when power is going through it - and if not submerged in water and does turn on and boiled dry I should imagine the thermal cut out would kick in and cut power to it and if a direct short of the element then blow the 13a fuse in the 13a 3 pin plug of the washing machine or blow a component on the main circuit board or even a fuse on the circuit board. - I think the thermal cut out would even work at say if heat got to about 124'c maximum , think that's what most are rated at . 

3.) That's the washing machine motor and the heating element covered both (well modern ones for the last 5 years or more I would say has protection on the main circuit board that would blow / fuse before a motor or element would get to the stage of catching fire? 


So what is left that could catch fire on a washing machine if left on overnight whilst asleep or out and about with the washing machine left on (and especially in a modern washing machine?) 

Could it be that "washing Machines shouldn't be left on when asleep or unattended because of risk of fire"  advice be confined to the waste bin now these days? (especially as I say now one of the selling points/features of the washing machines these days are that you can set a delay timer on them, and that a lot of people avail of doing their washing in off peak electricity times in the night whilst they are asleep , and busy working people wanting their washing done whilst they are out of the house and ready and washed by the time they come home. 

also taking into account in the old days they didnt have the same built in electrical protection as they do these days on the main circuit board/controller board the old heaters were more powerful at the bottom of the tub (sometimes going up to 2.3kw) but these days because of economy and washing at lower level of water have weaker elements in them and other eco features of the machine have made them safer?

- I would love to know what you think Andy on the subject maybe you know of other things that can cause a fire in a washing machine when left unattended you being a washing machine engineer for years. - do you think its still these days on modern washing machines dangerous to have them on when asleep and when out and about fire wise now , or was that mainly for old washing machines?

[Whitegoodshelp (Andy)]

Hello Andy. You make an interesting point as to whether washing machine fires are less likely these days, but my initial thoughts are that they are probably just as much a risk as they always were. If you search Google for the phrase, "fire caused by washing machine" there is a lot of very interesting information there. Including whitegoodshelp 🙂

I think the main cause of fires is overheating wiring, or water running onto electrical parts, causing a flash of electricity. I suspect dishwashers and tumble dryers are a higher risk, but washing machines definitely can catch fire. I'd like to think that if a washing machine is plugged into an RCD socket that it is less likely because they are extremely sensitive, and less likely to cause a big flash if anything shorts out.

Even the manufacturers of washing machines know that they catch fire. To me, it has always been irresponsible of them to incorporate delayed start functions. However, they have been using delayed start functions since at least the 1990s, so this is not something new. It's only the Wi-Fi function that is new.

In my opinion no amount of savings on electricity can justify the risk of leaving a washing machine, dishwasher, or tumble dryer to come on in the middle of the night when everyone is in bed. When I researched the subject, albeit some years ago now, I found that the amount of savings on this so-called reduced charges during the night schemes are pretty insignificant (White goods appliances and economy 7 overnight electricity savings). Although to be fair the savings are likely to be higher these days, but I would not take the risk.

If you look at my White goods appliance safety notices you'll see that the vast majority of them are where manufacturers themselves have warned that, sometimes millions of their appliances, could catch fire because of a design fault, or poor quality component.

I've written full articles on this subject like this one How dangerous are our appliances? And are more proactive Eight ways you can make your appliances more safe

I think ultimately it would be fair to say that it is still quite rare, but the consequences when it does happen can be absolutely catastrophic. Also if you have time, take a look at the real-life quotes from people who have experienced dishwasher fires that contacted me personally Examples of dishwasher fires

[andyr12345]

New thing coming in now under new UK wiring  regulations (if it hasn't come in already) are called 'Arc Arrestors) they will be fitted to all new consumer box installation I think. They are not cheap but they should help a lot in stopping shorts and fires from electrical appliances and faulty wiring in the home. They will detect shorts that RCD's RCCD's and RCCBO's cannot detect and cut power to the circuit - so that's one good thing to happen, of course in the case of a build up of lint / fluff in the tumble drier hose or filter it will not stop that , but if a component or wiring inside the appliance  starts sparking it may arrest it .