Last updated on February 6th, 2017
A Washing machine tripping or fusing electrics is a fault you can't really deal with unless you have electrical knowledge and an insulation test meter. However, you might be able to do some basic checks as described in this article. A fusing washing machine can be caused by more things than any other fault – virtually any part, or any wire, or any connection.
However, there is a list of usual suspects and some parts very rarely cause this fault. To diagnose a fusing washing machine you have to use an insulation test meter meter that puts 500 volts (DC) through the appliance and individual parts. This isn't a diy job. If you have the right equipment then you probably already know how to diagnose and deal with low insulation faults. If not, you should get someone in to look at it unless you can see something obvious like a chaffed wire.
Without an insulation test meter you can’t do proper insulation tests, but it may be worth testing with an ordinary multimeter if that’s all you have in case there is a direct short to earth. For example, if you test for continuity between the heating element pins and its earth tag or any part of the metal on the element (remove wires before testing) there should be no continuity. If you do get a reading, then electricity running through the heater will find a path to earth which can trip rcds or fuse the plug. The same applies to any other part such as the motor. There should be no continuity between any motor pin and earth (or the metal casing of the part). It is possible for a part to have a small leak to earth though that cannot be picked up with a normal continuity test meter. This is why a proper insulation test meter is needed. So, no reading between electrical connections and earth with a continuity test meter doesn’t prove there is no fault, but a continuity reading between pins and earth does mean there is an earth leakage.
The most common causes for a washing machine fusing electrics are –
- The motor
- The heater
- The suppressor
- A wire shorting out somewhere
- Water getting onto an electrical part
Observe when it is tripping the electrics
The correct way to troubleshoot a fusing washing machine is to test it with a proper insulation test meter but if I didn't have one I'd try to get some clues by observing exactly when the machine trips out. If it's immediately you turn it on it could be the suppressor (suppressors and capacitors can give a nasty shock even when unplugged!).
If it only tripped out after it had started filling with water and the drum first started to turn, then maybe it's a fault on the motor. If you suspect the motor then it should also trip on spin.
If it doesn’t trip the electrics on spin, but it does on wash then suspect the heater. (removing the heater from washing machine). If it only trips out on spin though, it could be a bare wire in the wiring somewhere that's touching something metal when the drum is bouncing around. This can often be intermittent and only tripping with large loads when the drum bounces around much more.
Process of elimination
The first thing to check is always for any snagged wires, worn wires where the plastic insulation has worn off and is touching something metal (sometimes only when the tub swings about on spin with a load in) or a wire which has come away from its connector.
Normally I would test the insulation of the washing machine down the plug, if low insulation is detected I either unplug parts until it clears, or unplug and test parts directly according to the main suspect list above.
If washer has tripped the RCD or fused the plug and now won’t work properly
Most people will naturally try the washer again by either resetting the electrics or replacing a blown fuse. Occasionally the washer might work ok and appear to have suffered no ill effects. If so, keep an eye on it. If it does it again try to observe when it does it as described above to get clues of possible suspects.
If after resetting the trip board or replacing the fuse the washer isn’t working properly then whatever fused out has failed completely or damaged something else. If nothing is working at all other than some lights it could be the main suppressor or main pcb. If the motor no longer runs it could be that the motor is the problem and it’s failed completely but it could also have blown something on the pcb. Without the right knowledge and a proper insulation test meter you need to call in an engineer.
Fused and door won’t open
If the door won’t open and the washer has tripped the electrics it could have fused the door interlock inside though this should only usually happen if there was a big flash and maybe there isn’t an RCD trip fitted (which should trip fast enough to not blow parts inside). Here’s an article on Washing Machine Door Will Not Open