Washing machine trips RCD but only on program 3 !

grimkin

Hi all,

We have a Hotpoint WML730, must be over 6 years old now .. I've replaced bits and pieces over the last couple of years - door rubber, brushes etc but now it has started to trip the fusebox, the last time with a PCB-burning smell and an audible pop from the appliance.

I've tested all other programs and this only happens on program #3 - the "coloureds" program - cottons, fast wash, pump, spin etc are all fine.

I'm guessing this is down to a component specific to that program but not sure what it could be - is it time to replace the machine?

Any ideas / opinions appreciated!

thanks

Alanp

The favourite for tripping a fuse is the heating element, as soon as the washer calls for heat and the element comes in , it trips , a quick way to test this is to disconnect the wires at the element ( make sure they are kept apart and can’t touch anything metal) and run the m/c again , if it still trips then it’s likely it’s something else..

grimkin

Thank you Alan! I'll do that.

Ganga

grimkin said:

Thank you Alan! I'll do that.

Make sure the machine is unplugged when you do this.

grumbler

Alanp said:

The favourite for tripping a fuse is the heating element, as soon as the washer calls for heat and the element comes in , it trips , a quick way to test this is to disconnect the wires at the element ( make sure they are kept apart and can’t touch anything metal) and run the m/c again , if it still trips then it’s likely it’s something else..

This can explain neither why it happens only in one regime "coloureds", nor the "PCB-burning smell and an audible pop".

Section62

grimkin said:

Thank you Alan! I'll do that.

I wouldn't do that.  It isn't safe, and if the element was faulty then it would also trip on other programmes.

Trying this test is also likely to cause the machine to 'lock up' - the controller won't continue the programme until it senses the water has been heated to the correct temperature, which won't happen because the heater is disconnected.

There's nothing obvious used in a "coloureds" programme which isn't used in the others, and other programmes such as cottons will make the machine work harder so would be more likely candidates for causing a failure by say overheating.

A burning smell and 'pop' indicates components are life-expired.  Given the frequency of house fires caused by failing white goods, the sensible advice is to switch the machine off, unplug it, and either get a professional to investigate, or just buy a new one.

Alanp

Section62 said:

grimkin said:

Thank you Alan! I'll do that.

I wouldn't do that.  It isn't safe, and if the element was faulty then it would also trip on other programmes.

Trying this test is also likely to cause the machine to 'lock up' - the controller won't continue the programme until it senses the water has been heated to the correct temperature, which won't happen because the heater is disconnected.

There's nothing obvious used in a "coloureds" programme which isn't used in the others, and other programmes such as cottons will make the machine work harder so would be more likely candidates for causing a failure by say overheating.

A burning smell and 'pop' indicates components are life-expired.  Given the frequency of house fires caused by failing white goods, the sensible advice is to switch the machine off, unplug it, and either get a professional to investigate, or just buy a new one.

The m/c will fill with water,and at some point it will bring on the heating element, if the fuse trips then it’s a fair sign the element is tripping, it may show a fault code, but your only testing it , your not going to leave it like that, of course it could be anything causing it to trip, you could, take the back and top off and ( unplugged of course) have a good look around to see if there are any signs of burning on any wiring or component, if you are in doubt, then call a professional..

Annemos

Until I read this post, I hadn't even thought about this. If one does predominately 30 degree washes, does the element last much longer compared to if one was to do more regular hotter washes?  

(Is that a daft question? Sorry if it is!) 

Alanp

They can still scale up if your in a hard water area which will reduce the effectiveness of the element, always a good idea to run a hot wash every so often 

Section62

Alanp said:

The m/c will fill with water,and at some point it will bring on the heating element, if the fuse trips then it’s a fair sign the element is tripping, it may show a fault code...

The point I made is that the heating element will be used on other programmes (except cold/'no heat' ones) and therefore if the element is faulty then the machine would cause the tripping problem with more than the one programme.

Barring something very unusual about the design of the OP's machine, the possibility of a faulty element can be ruled out just from the symptoms - there's no need to carry out a potentially dangerous (and quite likely inconclusive) test to work this out.

Alanp said:

...but your only testing it , your not going to leave it like that, of course it could be anything causing it to trip, you could, take the back and top off and ( unplugged of course) have a good look around to see if there are any signs of burning on any wiring or component, if you are in doubt, then call a professional...

Likewise the "PCB-burning smell" is not something which would point towards a faulty element. 

The smell, in conjunction with the fault only happening with one programme, would suggest a fault within the control circuitry - and on a machine of that age the chances of being able to carry out an economical repair are slim.  For safety reasons it would be better to leave it to a professional, or just replace the machine.

Bendy_House

Annemos said:

Until I read this post, I hadn't even thought about this. If one does predominately 30 degree washes, does the element last much longer compared to if one was to do more regular hotter washes?  

(Is that a daft question? Sorry if it is!) 

Not at all daft. And almost certainly the element will last longer on cooler washes.

Regardless of the wash temp set, the element almost certainly still comes on 'full' for however long it takes to get the water to that temp. But to get to a 30oC wash will obviously occur much more quickly than a 90oC one. So the element will be used for a much shorter period of time.

I suspect the cooler water temp, as it gets to only 30oC, will also cushion the stress on the element a bit more too, so even the element's 'core' temp (from the actual heating wire) will be conducted away more quickly by the cooler water. Whereas, with the water at 90oC, the whole element is likely to be much hotter throughout.