Washing machine carbon brushes are one of the most common parts to wear out. Each time the washing machine is in use they are physically wearing away. This page gives free diagnostic help and advice for competent repairers who may want to confirm and check a few things before replacing carbon brushes in a washing machine motor.
The principles of diagnosing carbon brush faults, and deciding if they need replacing are exactly the same as for any motor with carbon brushes fitted across all brands.
How do I know if I need to fit new carbon brushes?
I often see where people have fitted new brushes and the motor still doesn’t work. Don’t fit them speculatively. It’s common for people to see that brushes are worn, and probably need replacing – but this doesn’t mean it will get your motor running again. If a motor stops running, it can also be caused by many other faults. So unless you know the brushes need replacing don’t waste your time and money.
If you observe lots of sparking from inside the motor then this may also a symptom. However, very small sparks are usually normal and not necessarily a fault.
You should be competent enough to be able to diagnose and repair this type of fault because other faults could be present. You should always test a motor’s insulation with a suitable insulation test meter to ensure electrical safety using 500V DC. Low insulation on a motor could blow electronic parts inside a PCB.
Worn Carbon brushes
Here is a picture of a pair of worn Hotpoint carbon brushes. Both carbon brushes are approximately 80% worn but the carbon brush on the left is still making good contact with the armature.
The difference between the two is that the faulty one on the right is charred and sooty at the tip. It’s taken on a charcoal-like appearance and there is evidence of burning present. The good carbon brush on the left is smooth and shiny at the tip which shows no sparking has been occurring.
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If both brushes are smooth like the one on the left, then they are still making good contact and are not likely to be causing any symptoms. However, if they are as worn down as this they clearly still need replacing. It’s just that maybe the fault you currently have is caused by something else.
This carbon brush is OK
This Hotpoint (or Creda) carbon brush is about 20% worn. The tip of the brush (that runs against the armature) is shiny and smooth, with no evidence of burning. It is therefore perfectly alright.
It is possible for a carbon brush that is not worn down significantly to stick inside the holder (which is spring loaded) If this happens, then as the brush surface wears through normal usage, the brush doesn’t get moved up and stops making contact with the armature.
If this happens, then the tip of the carbon brush will look charred like the 80% worn one above.
Complications on carbon brushes
This carbon brush is approximately 50% worn but something has gone seriously wrong. If yours looks like this then there could be problems with the other parts inside the motor.
The tip of the carbon brush is charred but note the arcing damage to the brass holder which has been caused by excessive sparking and flashing inside the motor.
If the tip of the carbon brush is damaged to the extent that there is a chunk broken off, (not shown here) then there is a good chance that a raised commutator bar on the armature has caused the fault. This would require a new motor. A raised or loose comm bar can be felt by placing a finger on the copper segments and slowly turning the armature.
If the washing machine has also fused, then this is evidence of electrical shorting inside the motor which you need an insulation test meter and electrical knowledge to diagnose and repair.
Also, if there is damage like this on the brass holder (and especially if the washing machine fused) then the TOC could have blown also. This is then not a simple case of replacing the worn carbon brushes and no longer a straight forward DIY repair job.
Potential Complications
Fitting new brushes in a motor is relatively simple. However, it can also come with complications and you may ultimately just be wasting your time if you haven’t got experience working with motors and you don’t have proper test equipment. See the extra information in related articles below but give serious consideration to getting a proper repair engineer to look at it.
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kumar says
During spin cycle some flasing lights are coming from near motor.what is that?im using front loading washing machine
Whitegoodshelp (Andy Trigg) says
One of the symptoms of worn carbon brushes that may need replacing is flashing and sparking when running. However, it could also be a symptom of the main armature being worn too.
kumar says
Some tell its normal for a carbon motor to produce little light while it spins.is it true? IM using front load washer
Whitegoodshelp (Andy Trigg) says
Yes small sparking (blue coloured) is usually nothing to worry about. It’s “flashes” which are not good. Any motor sparking enough to cause flashes of light to reflect in the floor underneath it or that are going all around the armature or creating noise should be investigated.
kumar says
Its small sparking whiteblue in colour,it appearsduring spin,and it is noticible only extremely dark room.is it normal?asking regarding front loading washer.there is no smell at all.
Whitegoodshelp (Andy Trigg) says
Sounds fine.
Amanda says
My hotpoint washing machine is not going through its cycle correctly. Sometimes doesn’t rinse & at others won’t spin. Can go back & do these individually on machine. Does this sound like the brushes need replacing?
Whitegoodshelp (Andy Trigg) says
No it doesn’t Amanda unless when you say sometimes it doesn’t rinse or go through its cycle properly that you just mean the motor stops running. Carbon brushes can cause intermittent symptoms but they usually just mean the motor works sometimes and not others. The wash cycle would normally complete with just the drum not turning although these days most washers should report a motor error code. A few (like some Hotpoint and Indesit models) can go completely dead if the brushes stop making contact. The lights work but everything else is completely dead.
If you suspect brushes, this article shows you how to check them although it doesn’t give instructions on how to take them out. You need to know what you are doing. This article here looks at some reasons why one might stick mid-cycle Washing machine sticks or stops mid-cycle
Kim says
Would worn carbon brushes be giving off a smell and slight noise, sort of rubbing?
Andy Trigg says
Kim: worn carbon brushes which are sparking heavily can give off a smell of burning. They also make a grating noise or slight crackling noise which is the noise of the sparks.